Pen Analog Front End Circuit for Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current multimedia electronic devices lack an efficient pen input system that provides fine touch input for writing and drawing applications, with existing solutions often suffering from noise interference and compatibility issues with various devices.
Innovation Solution
A pen analog front end is developed, comprising an analog signal processing unit and a digital signal processing unit, which includes a charge amplifier, band pass filter, analog-to-digital converter, data storing unit, bit synchronization unit, burst synchronization unit, and processing unit, to process and synchronize magnetic field signals from a pen input device, reducing noise and enhancing compatibility with various devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If magnetic field signals are used for pen input communication, then compatibility with various devices is improved, but noise interference increases
Solution Approach 1:
The patent introduces an analog front end circuit as an intermediary between the magnetic field signal receiver and the digital processing unit. This circuit includes a band-pass filter that selectively passes only the frequency range of the pen input signal (e.g., 150-250 kHz), blocking out-of-band noise and interference. The filter acts as a mediator that allows the magnetic field communication to maintain compatibility while rejecting harmful noise signals.
Solution Approach 2:
The patent employs parameter changes by adjusting the center frequency and bandwidth of the band-pass filter to match the specific magnetic field communication protocol being used. By dynamically tuning the filter parameters based on the detected signal characteristics, the system maintains optimal noise rejection while preserving compatibility with different pen input devices that may operate at slightly different frequencies.
2Measurement precision
If signal processing complexity is increased to reduce noise, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent segments the signal processing function into distinct modular stages: (1) magnetic field signal reception, (2) analog band-pass filtering, (3) analog-to-digital conversion, and (4) digital signal processing. Each stage handles a specific aspect of noise reduction and signal enhancement, allowing the system to achieve high measurement precision without requiring all processing complexity to be concentrated in a single complex unit. This modular segmentation makes the overall system more manageable and maintainable.
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
The solution effectively processes and synchronizes pen input signals, reducing noise and improving compatibility, enabling precise and intuitive pen input operations across different electronic devices.
Implementation Method 1
The input signal may be a magnetic field signal transmitted by using a magnetic field
Implementation Method 2
analog signal processing unit connected with an input sensor. The analog signal processing unit processes an analog input signal that the input sensor receives from an input device
Data Source
AI summary
A pen analog front end includes an analog signal processing unit connected with an input sensor. The analog signal processing unit processes an analog input signal that the input sensor receives from an input device. An analog-to-digital converter converts the analog input signal into a first digital input signal. A digital signal processing unit synchronizes the first digital input signal and reference sync data preset to the input sensor and processes a position signal and a data signal of the input device.