Capacitive Touch Sensor Signal Line Segmentation
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Solution Overview
Problem
The challenge is to minimize parasitic capacitance while maintaining a fine detection function in touch sensors, particularly in projection-type electrostatic capacitive touch sensors, where increasing the number of wirings and narrowing their intervals lead to unintended capacitance issues.
Innovation Solution
The design incorporates a capacitive touch sensor with a touch detection area featuring narrow intervals between drive and detection signal lines, where detection signal lines are separated from each other in specific areas to reduce parasitic capacitance, allowing for finer detection without increasing the number of wirings and enabling a narrower frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of wirings is increased and the interval between wirings is narrowed to achieve fine detection function, then the detection precision is improved, but parasitic capacitance occurs
Solution Approach 1:
The detection signal lines are segmented into first signal lines and second signal lines based on their positional characteristics. First signal lines are disposed in areas where the interval between drive signal lines is narrow, while second signal lines are disposed in areas where the interval is wide, creating a segmented wiring architecture that addresses parasitic capacitance issues while maintaining detection precision
Solution Approach 2:
Different wiring configurations are applied to different regions of the touch sensor. In areas with narrow drive signal line intervals, detection signal lines are arranged to minimize parasitic capacitance effects, while in areas with wide intervals, different arrangements are used. This local optimization allows fine detection function to be maintained without excessive parasitic capacitance
2Measurement precision
If the number of wirings is increased to achieve fine detection function, then the detection precision is improved, but the frame width must be increased to accommodate the wirings
Solution Approach 1:
The patent utilizes both the first direction (along the drive signal lines) and the second direction (intersecting the first direction, along the detection signal lines) to arrange wirings efficiently. By configuring first and second signal lines with different orientations and positions, the design achieves fine detection function without requiring increased frame width in a single dimension
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 enhances the sensitivity of fingerprint authentication and touch detection while suppressing parasitic capacitance, allowing for a more compact and efficient touch sensor design.
Implementation Method 1
projection-type electrostatic capacitive touch sensor including a touch detection area in which a plurality of drive electrodes and a plurality of detection electrodes are disposed
Implementation Method 2
capacitive touch sensor including a touch detection area that includes a plurality of detection electrodes and a plurality of drive electrodes
Data Source
AI summary
A touch sensor is a capacitive touch sensor including a touch detection area that includes a plurality of drive electrodes and a plurality of detection electrodes, and includes a plurality of drive signal lines extending in the Y-axis direction and arranged in the X-axis direction, and a plurality of detection signal lines extending in the X-axis direction and arranged in the Y-axis direction. The touch detection area includes a fingerprint detection area F in which an interval between a plurality of drive signal lines and an interval between a plurality of detection signal lines are narrow, and the detection signal lines include fingerprint authentication signal lines disposed in a fingerprint authentication area and detection signal lines disposed to be electrically separated from the fingerprint authentication signal lines in an area, which is adjacent to the fingerprint authentication area in the X-axis direction, of the touch detection area.