Touch Sensor Laminate Flexibility via Connection Angle Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive touch screen panels with ITO patterns suffer from poor flexibility and are prone to damage due to contraction, expansion, or bending forces, which limits their use in flexible flat panel display devices.
Innovation Solution
A touch sensor laminate design featuring a polarizing plate with a sensing pattern layer, including a first pattern, a second pattern, and a bridge electrode, where the angle between the polarizing plate's stretching direction and the connection or bridge electrode's length direction is optimized to reduce damage from warpage, and an organic or inorganic layer is included for protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If ITO pattern is used as sensing pattern, then transparency is improved, but flexibility deteriorates and the pattern is easily fractured when contraction, expansion or bending force is applied
Solution Approach 1:
The sensing pattern is divided into multiple unit patterns arranged in a matrix, with connection portions linking adjacent units. This segmentation allows the pattern to flex and deform without causing catastrophic failure of the entire sensing structure, addressing the brittleness of conventional ITO patterns while maintaining transparency.
Solution Approach 2:
The patent employs a thin film structure for the sensing pattern layer that can bend and deform elastically. The connection portions are designed with specific geometric features that enhance flexibility, allowing the sensing pattern to withstand contraction, expansion, and bending forces without fracturing, thus achieving both transparency and flexibility.
2Reliability
If polarizing plate is stretched to improve flexibility, then flexibility is improved, but warpage occurs causing damage to sensing pattern over time
Solution Approach 1:
The connection portions are designed with asymmetric geometric features, including varying widths and specific angular orientations (60° or less relative to stretching direction). This asymmetric design compensates for the warpage induced by polarizing plate stretching, distributing stress unevenly to prevent pattern damage while maintaining overall flexibility.
Solution Approach 2:
The patent optimizes specific parameters of the connection portions, such as width ratios, angular orientations (60° or less), and length dimensions, to accommodate the dimensional changes caused by polarizing plate stretching. These parameter adjustments ensure the sensing pattern remains intact despite warpage, achieving both flexibility and long-term stability.
3Reliability
If connection portion width is reduced to improve flexibility, then flexibility is improved, but manufacturing precision requirements increase
Solution Approach 1:
The sensing pattern layer is formed as a composite structure combining multiple materials with different properties. The connection portions utilize materials and structural designs that provide both flexibility and manufacturability, balancing the need for narrow widths with practical manufacturing constraints through optimized composite material selection and layer configuration.
Data Source
AI summary
A touch sensor laminate includes a polarizing plate having a predetermined stretching direction, and a sensing pattern layer formed on at least one surface of the polarizing plate. The sensing pattern layer includes a first pattern formed along a first direction, a second pattern formed along a second direction, and a bridge electrode electrically connecting isolated unit patterns included in the second pattern. The first pattern includes a plurality of unit patterns, and a connection portion connecting neighboring unit patterns of the plurality of unit patterns, the connection portion having a width smaller than a maximum width of the unit pattern of the first pattern. An angle between the stretching direction of the polarizing plate and a length direction of the connection portion is 60° or less.