Digitizer Sensor Orthogonal Signal Detection
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Solution Overview
Problem
Current digitizer systems face limitations in report rate and efficiency for detecting user interactions, particularly in multi-touch scenarios, due to sequential activation of electrodes and limited frequency usage, which restricts their ability to handle multiple simultaneous inputs effectively.
Innovation Solution
The method involves simultaneously activating two electrodes with orthogonal signals of the same frequency, sampling signals at cross-junctions, decomposing these signals into orthogonal components, and analyzing them to detect user interactions, which enhances detection speed and accuracy by maintaining orthogonal signal relationships despite user presence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sequential activation of electrodes is used, then device complexity is reduced, but productivity (report rate) is limited
Solution Approach 1:
The patent applies parameter changes by using orthogonal signals with the same frequency instead of sequentially activating electrodes with different frequencies. This allows simultaneous activation of multiple electrodes, doubling the interrogation rate while maintaining signal distinguishability through orthogonality in the same frequency domain rather than requiring frequency differentiation.
Solution Approach 2:
The patent implements continuity of useful action by enabling simultaneous interrogation of multiple electrode pairs through orthogonal signaling. Instead of sequential scanning that creates idle time between measurements, the system continuously interrogates multiple locations at once, maximizing the utilization of the sensing infrastructure and doubling the effective report rate.
2Productivity
If multiple frequencies are used for simultaneous electrode activation, then productivity increases, but measurement precision deteriorates due to signal interference
Solution Approach 1:
The patent changes the parameter space from frequency differentiation to orthogonality in the same frequency domain. By using orthogonal signals (such as sine and cosine waves) at the same frequency, the system achieves simultaneous multi-electrode interrogation without the signal interference that plagues multi-frequency approaches, as orthogonal signals can be cleanly separated through correlation detection.
Solution Approach 2:
The patent introduces an intermediary mathematical operation (orthogonal decomposition or correlation detection) that allows simultaneous signals to be separated and analyzed independently. This intermediary process enables the system to handle multiple simultaneous signals without cross-talk, maintaining measurement precision while achieving higher interrogation rates.
3Reliability
If sequential electrode activation is used, then signal interference is minimized, but loss of time increases
Solution Approach 1:
The patent eliminates idle time between sequential interrogations by enabling simultaneous activation of multiple electrode pairs using orthogonal signals. The continuous useful action is maintained because all electrodes are being interrogated at the same time rather than taking turns, thereby reducing the total interrogation time while the orthogonality of signals ensures reliable detection without cross-interference.
Solution Approach 2:
The patent changes the temporal parameter from sequential timing to simultaneous timing with orthogonal phase relationships. By using signals that are orthogonal in phase (such as 0° and 90° phase-shifted signals), the system can simultaneously interrogate multiple electrodes without signal interference, reducing the time required while maintaining detection reliability.
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 doubles the interrogation rate and allows for accurate detection of multiple user interactions, including fingertips and objects, by maintaining signal orthogonality and correcting for predictable phase shifts, thereby improving the overall performance of digitizer sensors.
Implementation Method 1
sampling a signal on at least one other conductor crossing the at least two conductors, wherein the signal is responsive to capacitive coupling at cross-junctions formed between the at least two conductors and at least one other conductor
Data Source
AI summary
A method for detection on a digitizer sensor, the method comprises simultaneously transmitting orthogonal signals having the same frequency on at least two conductors of a digitizer sensor; sampling a signal on at least one other conductor crossing the at least two conductors, wherein the signal is responsive to capacitive coupling at cross-junctions formed between the at least two conductors and at least one other conductor; decomposing the sampled signal into orthogonal components; and analyzing the orthogonal components to detect user interaction at each cross junction.