Projected Capacitance Touchscreen Thickness Reduction via Polarizer Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing projected capacitive touchscreens face challenges in reducing thickness while maintaining mechanical strength and controlling manufacturing costs, as forming ITO conductive circuits on the cover lens either increases processing difficulty or raises costs.
Innovation Solution
The solution involves forming the first and second direction sensing electrodes on the upper polarizer, eliminating the need for a substrate and allowing the cover lens to be manufactured without additional reinforcement, thereby reducing thickness without increasing costs and ensuring mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the ITO conductive circuits are formed on the surface of the cover lens before the cover lens is cut, then the thickness of the touchscreen is reduced, but the cover lens cannot be reinforced and processing difficulty increases
Solution Approach 1:
The patent divides the touchscreen structure into separate functional layers: the cover lens is cut and reinforced first as an independent component, then the ITO conductive circuits are formed on its surface as a separate step. This segmentation allows each component to be optimized independently without interfering with the other processes.
Solution Approach 2:
The cover lens is cut and reinforced in advance before the ITO conductive circuits are formed on its surface. This preliminary action ensures the cover lens has the required mechanical strength before the subsequent ITO deposition process, resolving the contradiction between thickness reduction and manufacturing ease.
2Strength
If the ITO conductive circuits are formed on the surface of each cover lens after the cover lens is cut and reinforced, then the mechanical strength is maintained, but manufacturing costs are largely increased
Solution Approach 1:
The patent merges the ITO conductive circuit formation process with the existing touchscreen manufacturing process by forming the ITO circuits on the cover lens surface as part of the overall assembly process, rather than as a separate post-processing step for each individual lens. This integration reduces manufacturing costs while maintaining the mechanical strength benefits of pre-reinforcement.
3Length of stationary object
If a large lens is reinforced before the ITO conductive circuits are formed on the surface and is then cut into small lens, then the thickness is reduced, but processing difficulty is increased due to high hardness of the large lens
Solution Approach 1:
The patent inverts the conventional manufacturing sequence by first cutting the cover lens into the required small sizes, then reinforcing the individual small lenses, and finally forming the ITO conductive circuits on their surfaces. This reversed sequence avoids the difficulty of processing large hardened lenses while achieving the same thickness reduction goal.
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 reduces the touchscreen's thickness without elevating manufacturing costs and ensures high mechanical strength of the cover lens, addressing the dual concerns of cost and mechanical integrity.
Implementation Method 1
an upper polarizer, a bonding layer, and a cover lens... The first direction sensing electrodes 3 and the second direction sensing electrodes 5 are ITO (Indium tin oxide, indium tin oxide) conductive circuits that are formed on top and bottom surfaces of the substrate 4
Implementation Method 2
When a user touches the cover lens 7 with a finger, capacitance between the first direction sensing electrodes 3 and the second direction sensing electrodes 5 in the touch position changes, and an electrostatic current that flows from the human body to the ground also changes accordingly
Implementation Method 3
The bonding layer 6 is configured to bond the cover lens 7 to the second direction sensing electrodes 5
Data Source
Figure 1a~2
Figure 3~4
Figure 5
AI summary
Embodiments of the present invention provide a projected capacitive touchscreen and a manufacturing method thereof. In the embodiments of the present invention, sensing electrodes and a polarizer are overlaid to form a sensing assembly, so that a substrate used in the sensing assembly in the prior art is not required, and that the sensing electrodes do not need to be formed on a cover lens. Therefore, thickness of a touchscreen is reduced without increasing manufacturing costs because the cover lens can be manufactured according to an existing process. Further, high mechanical strength of the cover lens is ensured, thereby achieving a purpose of taking both the manufacturing costs and the mechanical strength of the cover lens into consideration after thickness of a projected capacitive touchscreen is reduced.