Touch Sensor Electrode Layout for Accurate Pen Position Detection
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Solution Overview
Problem
Existing position detection devices face challenges in accurately determining the position of a pen due to varying interconnect resistance in the reception path of the pen signal, which is influenced by the pen's position on the touch surface, leading to reduced accuracy.
Innovation Solution
The sensor electrodes and routing lines are designed to have continuously or stepwise decreasing interconnect resistance per unit length based on their distance from the connection point with the routing lines, reducing the difference in interconnect resistance between any two sensor electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If routing lines are connected to sensor electrodes at different positions, then the sensor can cover a larger detection area, but the interconnect resistance difference among routing lines increases
Solution Approach 1:
The routing lines are designed with non-uniform line widths, where the line width varies at different segments of the routing path. Specifically, routing lines have wider sections closer to the terminal group and narrower sections farther away, creating local variations in electrical properties that compensate for the different path lengths and achieve uniform interconnect resistance across all sensor electrodes.
2Adaptability or versatility
If the routing line length varies for different sensor electrodes, then the sensor can accommodate different pen positions, but the interconnect resistance difference increases
Solution Approach 1:
The electrical parameters of the routing lines, specifically the line width, are changed along the routing path to compensate for variations in path length. By adjusting the line width parameter, the resistance per unit length varies inversely with the distance from the terminal group, ensuring that the total interconnect resistance remains substantially constant across all sensor electrodes regardless of their positions.
Data Source
AI summary
Provided is a sensor including sensor electrodes disposed from a first end to a second end in a first direction in a touch surface, terminals that are each disposed for a corresponding one of sets of sensor electrodes among the sensor electrodes and connected to a sensor controller, and routing lines that connect each of the sensor electrodes to one of the terminals corresponding to one of the sensor electrodes. An interconnect resistance per unit length of each of the sensor electrodes becomes lower continuously or in a stepwise manner, according to an interconnect distance from a portion connecting with one of the routing lines corresponding to one of the sensor electrodes, and a difference in the interconnect resistances between any two sensor electrodes among the sensor electrodes is smaller than a case in which an interconnect resistance per unit length in each of the routing lines is constant.