Pen Reception Circuit for Dull Uplink Signal Edge Detection
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Solution Overview
Problem
Existing methods struggle to accurately detect edges in uplink signals due to waveform dullness, making it difficult for pens to receive transmission data effectively.
Innovation Solution
A method involving a sensor controller that generates pulse signals with enhanced edges using a main and sub signal, and a pen with a differential circuit and ΔΣ modulation unit to enhance edge detection, allowing for proper reception of uplink signals despite waveform dullness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the sensor controller transmits uplink signals through the sensor electrode group, then data communication between the position detection apparatus and the pen is enabled, but the waveform of the uplink signal becomes dull making edge detection difficult
Solution Approach 1:
The uplink signal is segmented into multiple frequency components through pulse signal transmission. The sensor controller transmits the signal as a pulse waveform containing rich high-frequency components, which are then segmented and processed by the bandpass filter in the pen to extract edge information effectively despite waveform dullness
Solution Approach 2:
The patent applies signal vibration principles by transmitting the uplink signal as a pulse waveform with high-frequency components. This vibration-like signal structure enhances edge detectability through the bandpass filter, allowing the pen to detect edges even when the overall waveform appears dull or degraded
2Device complexity
If the pen uses simple edge detection methods, then the device complexity is reduced, but it cannot detect edges when the waveform is dull
Solution Approach 1:
A bandpass filter is introduced as an intermediary component between the signal input and edge detection circuits. This filter mediates the signal processing by selectively passing high-frequency components associated with edges while attenuating low-frequency dullness, thereby improving edge detection reliability without significantly increasing overall system complexity
Solution Approach 2:
The patent changes the frequency domain parameters of the signal by using pulse transmission with specific frequency characteristics. The bandpass filter is configured with specific frequency parameters to target edge-related high-frequency components, transforming the detection problem from time-domain edge detection to frequency-domain selective filtering followed by simplified edge detection
Data Source
AI summary
A reception circuit of a pen is provided. The reception circuit includes a differential circuit that detects edges of a signal received by the pen. The reception circuit includes a ΔΣ modulation unit that uses at least two reference potentials corresponding to positive and negative values, to compare an output signal of the differential circuit and the two reference potentials and that executes feedback processing of comparison results. The ΔΣ modulation unit uses two or more first comparators corresponding to positive values and two or more second comparators corresponding to negative values to execute folding modulation. The reception circuit includes a digital circuit that performs a correlation operation of an output signal of the ΔΣ modulation unit and known patterns to detect transmission data based on the signal.