Diode-less Keyboard Ghost Key Detection via Resistance Voltage Division
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Solution Overview
Problem
Conventional keyboards face the 'ghost key phenomenon' where the displayed text on a monitor does not match the input text, leading to increased component costs and circuit complexity when attempting to mitigate this issue.
Innovation Solution
A resistance-type keyboard with a division module that generates voltage levels from resistance values, allowing a control module to accurately determine which key is pressed and provide corresponding control information to a host device, thereby avoiding the ghost key phenomenon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a plurality of diodes are disposed in the keyboard to avoid ghost key phenomenon, then the reliability of key detection is improved, but the device complexity and component cost increase
Solution Approach 1:
The patent extracts the diode component from the keyboard circuit entirely, replacing it with a diode-less design that uses a simple resistor network and microcontroller-based detection algorithm to identify ghost keys, thereby reducing component count and circuit complexity while maintaining detection reliability
Solution Approach 2:
The patent replaces the hardware-based diode protection mechanism with a software-based detection and correction algorithm in the microcontroller, substituting physical components with computational logic to achieve the same ghost key prevention function
2Reliability
If conventional circuit layout design is used to avoid ghost key phenomenon, then the reliability of key detection is improved, but the manufacturing cost increases
Solution Approach 1:
The patent uses inexpensive standard resistors and a basic microcontroller instead of costly specialized keyboard controller ICs, opting for affordable, readily available components that simplify manufacturing while achieving reliable ghost key detection through software algorithms
3Measurement precision
If resistance values are used to generate voltage levels for key detection, then the measurement precision of key press detection is improved, but the device complexity increases
Solution Approach 1:
The patent replaces complex analog voltage comparison circuits with a digital microcontroller that reads resistance values through ADC (analog-to-digital converter) pins and uses software algorithms to determine key press status, simplifying the hardware while maintaining or improving detection precision
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 solution effectively reduces component costs and circuit complexity while accurately determining key presses, enhancing keyboard accuracy and functionality by using resistance values to generate voltage levels and control information.
Implementation Method 1
When an object presses a specific key, the specific key generates a resistance value according to a force applied by the object
Implementation Method 2
The division module receives the resistance value and generates a voltage level according to the resistance value and a first level
Data Source
AI summary
An input device provides control information to a host device and including a plurality of keys, a division module and a control module is disclosed. When an object presses a specific key, the specific key generates a resistance value according to a force applied by the object. The division module receives the resistance value and generates a voltage level according to the resistance value and a first level. The control module generates the control information according to the voltage level. The host device executes a function corresponding to the specific key according to the control information.