Stylus Speed Detection Using Digitizer Uplink Signal Patterns
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Solution Overview
Problem
Existing methods for determining stylus speed on a digitizer are inaccurate and introduce lag due to the need for speed information to be transmitted from the digitizer to the stylus, which can cause delays in applications like haptic feedback.
Innovation Solution
A stylus equipped with a sensor to receive uplink signals from a grid of antennas in the digitizer, using a predetermined spatial pattern of ping signals to determine its speed directly, eliminating the need for transmission and reducing lag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If speed information is determined by the digitizer and transmitted to the stylus, then the speed can be used for applications like haptic feedback, but this method is slow due to transmission delays
Solution Approach 1:
The stylus performs self-measurement of its speed by detecting the sequence of uplink signals from the antenna grid itself, eliminating the need for the digitizer to calculate and transmit speed information. This self-service approach resolves the contradiction by enabling the stylus to obtain accurate speed information instantaneously without transmission delays.
2Loss of time
If an accelerometer onboard the stylus is used to estimate speed, then the speed information is available at the stylus quickly, but the accuracy is quite poor
Solution Approach 1:
The patent replaces the mechanical accelerometer-based speed estimation with an electromagnetic field-based measurement system. The stylus detects the sequence of uplink electromagnetic signals from the antenna grid to determine its speed, substituting the mechanical sensing approach with an electromagnetic field interaction approach that provides both rapid response and high accuracy.
Solution Approach 2:
The uplink signals from the antenna grid serve as an intermediary medium between the stylus and the speed measurement function. Instead of directly measuring mechanical acceleration, the system uses the electromagnetic signals as a mediator to encode position information that the stylus decodes to calculate speed, achieving both speed and accuracy.
3Measurement precision
If the stylus determines its own speed using uplink signals from the antenna grid, then both accuracy and speed are improved, but this requires the stylus to process signal sequences
Solution Approach 1:
The digitizer pre-establishes a known spatial-temporal pattern of uplink signals across the antenna grid before the stylus arrives. This preliminary configuration of the signal field allows the stylus to simply detect and compare the received signal sequence against the known pattern, reducing the processing complexity to pattern matching rather than complex signal analysis.
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
Enables fast and accurate determination of stylus speed at the stylus itself, improving user experience by reducing delays in haptic feedback and other applications.
Implementation Method 1
a sensor configured to receive uplink signals emitted by a grid of antennas in the digitizer
Data Source
AI summary
A device for use with a touch surface digitizer, the device comprising: a sensor configured to receive uplink signals emitted by a grid of antennas in the digitizer, and a controller configured to detect the uplink signals via the sensor; wherein the controller is further configured to determine a speed of the device based on a detected sequence of the uplink signals as received at the sensor from one or more junctions of the antenna grid relative to a predetermined spatial pattern of the uplink signals as emitted across the grid.