Touch Detector Scanning Pitch Control for Resolution Sensitivity Trade-off
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Solution Overview
Problem
Capacitance system touch detectors face a trade-off between detection sensitivity and position resolution, where increasing detection sensitivity leads to rough scanning and reduced position resolution due to wider drive electrodes.
Innovation Solution
A touch detector design with multiple drive electrodes arranged side by side, where a scanning drive section selectively applies touch detection drive signals with pulse waveforms to a subset of electrodes in a time-divisional manner, achieving a scanning pitch smaller than the total width of the selected electrodes, thereby improving position resolution while maintaining detection sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the width of drive electrode is increased to improve detection sensitivity, then detection sensitivity is improved, but scanning pitch is increased causing rough scanning and position resolution is deteriorated
Solution Approach 1:
The drive electrode is divided into multiple segments (first drive electrode and second drive electrode) arranged side by side. This segmentation allows independent control of each segment, enabling the system to achieve fine scanning pitch through selective activation while maintaining overall wide coverage for high detection sensitivity.
Solution Approach 2:
The patent employs dynamic control of electrode selection through the scanning drive section. By selectively applying drive signals to different combinations of electrode segments based on touch detection needs, the system can dynamically adjust the effective scanning pitch independent of the physical electrode width, resolving the contradiction between sensitivity and resolution.
2Productivity
If line-sequential scanning is performed on common electrode to perform display operation, then display function is achieved, but touch detection operation requires separate scanning process
Solution Approach 1:
The drive electrodes are designed to serve dual functions: they act as common electrodes for display driving and as touch detection electrodes simultaneously. The scanning drive section controls these electrodes to perform both display scanning and touch detection scanning, eliminating the need for separate electrode structures and reducing system complexity.
Solution Approach 2:
The patent merges the display drive function and touch detection function into a single electrode structure and scanning mechanism. By combining these functions, the system reduces the number of separate scanning processes needed while maintaining both display performance and touch detection capability.
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 allows for high position resolution and enhanced detection sensitivity, enabling precise touch detection with independent control over scanning pitch and touch detection width, simplifying the configuration of the touch detection section.
Implementation Method 1
The detection electrode extends in a direction orthogonal to a direction where the drive electrodes extend, and is arranged to form a capacitance at each of intersections with the drive electrodes
Data Source
AI summary
A touch detector capable of achieving high position resolution while improving detection sensitivity to a touch is provided. The touch detector includes: a plurality of drive electrodes arranged side by side to extend in one direction; a detection electrode extending in a direction orthogonal to a direction where the drive electrodes extend, and arranged to form a capacitance at each of intersections with the drive electrodes; and a scanning drive section sequentially selecting a predetermined plural number of target electrodes from the plurality of drive electrodes in a time-divisional manner, and applying a touch detection drive signal with a plurality of pulse waveforms for detecting an external adjacent object to the selected target electrodes to perform a scanning drive. A scanning pitch in the scanning drive is smaller than the total width of the plural number of selected target electrodes.