Optical Switch Keyboard Scan Signal Period Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical switch keyboards face issues with decreased illuminating efficiency over time, leading to misjudgment of key presses due to reduced light intensity and shortened or delayed high voltage intervals in detecting electric signals.
Innovation Solution
A method that adjusts the scan signal period and delay period to ensure correct voltage reading, activating a correction mode when the signal is outside the pressed state voltage range, and terminating it when within, to accurately determine key presses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the light source emits scanning light over a long period of time, then the light source can maintain operation, but the illuminating efficiency decreases and light intensity reduces
Solution Approach 1:
The patent implements dynamic adjustment of the scan signal period based on detected light intensity levels. The control unit monitors the detecting electric signal characteristics and automatically increases the scan period when light intensity drops below thresholds, allowing the system to adapt to aging light sources and maintain reliable key detection throughout the keyboard's operational life
Solution Approach 2:
The patent changes the temporal parameter (scan signal period) in response to degradation in optical performance. By adjusting the period between scan signals based on measured light intensity, the system compensates for the natural aging of the light source, extending the functional lifespan while maintaining detection accuracy
2Measurement precision
If the light intensity reduces, then the high voltage interval of the detecting electric signal is shortened or delayed, but the control unit needs to read the correct voltage to determine key press state
Solution Approach 1:
The patent employs feedback mechanisms where the control unit monitors the detecting electric signal characteristics (voltage levels and timing) and uses this information to adjust the scan signal period. This closed-loop approach ensures that even when light intensity reduction causes timing shifts in the detecting signal, the control unit compensates by reading at appropriately adjusted time points, maintaining measurement precision
Solution Approach 2:
The patent performs preliminary detection of the detecting electric signal characteristics before making determination decisions. By analyzing the voltage levels and timing of the detecting signal in advance, the control unit can identify when timing shifts occur due to light intensity reduction and proactively adjust its reading strategy to capture accurate key press state information
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 method ensures accurate determination of key presses by compensating for decreased light intensity, preventing misjudgment and maintaining keyboard functionality.
Implementation Method 1
the optical switch keyboard is operated through a light generated by a light source (such as a light-emitting diode) and a corresponding detecting element (such as a phototransistor)
Data Source
AI summary
A method for adjusting an optical switch keyboard and an optical switch keyboard using the adjusting method are provided. The optical switch keyboard has a number of key units. The method includes the following steps. A scan signal is applied to one of a number of scan lines by a control unit at a first scan time point. A light is emitted by a light source according to the scan signal. A light emitted by the light source is detected by a detecting element to generate a detecting electric signal. The detecting electric signal is read by the control unit to obtain a first read signal voltage. When the first read signal voltage is outside the voltage range of the pressed state of the key unit, the period of the scan signal is increased by a first predetermined amount by the control unit to obtain an adjusted scan signal.