Ambient Light Sensor Switching LED Backlight for Mobile Keyboards
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Solution Overview
Problem
Conventional mobile telephone keyboards with LED background lighting consume excessive power as the lighting is not switched off in sufficient light environments, affecting communication time and standby period due to fixed lighting settings.
Innovation Solution
An apparatus comprising a light sensor, decision device, and light source that switches off the light source when ambient luminance exceeds a predetermined value, using a light sensor to sense luminance and output a switching signal to control the decision device, which determines whether the light source should emit light based on the sensing signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the LED background light is continuously activated, then the keyboard lighting function is always available, but the power consumption increases significantly
Solution Approach 1:
The patent applies dynamics by making the LED background light switchable between on and off states based on ambient light conditions. The light sensor continuously monitors the environment and dynamically adjusts the LED state accordingly - keeping it on when ambient light is insufficient and turning it off when ambient light is sufficient, thus adapting the system behavior to changing conditions rather than maintaining a fixed state
Solution Approach 2:
The patent implements feedback by using a light sensor to detect ambient luminance levels and feed this information back to the control logic. The system continuously monitors the light environment and uses this feedback signal to automatically control the LED background light, creating a closed-loop control system that adjusts power consumption based on actual lighting needs
2Reliability
If the battery capacity is increased to support continuous lighting, then the lighting function is maintained, but the device volume and weight increase
Solution Approach 1:
The patent applies self-service by enabling the device to automatically monitor its own ambient light environment and autonomously control the background light without requiring manual user intervention. The light sensor and control circuit work together to automatically switch the LED on or off based on detected light levels, allowing the device to serve its own lighting control needs and eliminate the need for larger batteries to support continuous operation
3Ease of operation
If the LED is not switched off in sufficient light, then the keyboard lighting remains available, but the communication time and standby period are reduced
Solution Approach 1:
The patent applies parameter changes by monitoring the ambient light parameter (luminance level) and using this parameter to control the LED state. When the ambient light parameter exceeds a certain threshold, the system changes the LED state from on to off, and when the parameter falls below the threshold, it switches the LED back on, thus using parameter variation to optimize both usability and battery duration
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 prevents unnecessary power consumption by switching off the light source in sufficient light environments, optimizing battery power usage, extending communication hours and standby periods, and improving design flexibility and production practicability.
Implementation Method 1
a light sensor senses the ambient luminance and outputs a sensing signal
Data Source
AI summary
An apparatus and its corresponding method for switching a light source are provided. The apparatus includes a light sensor, a decision device and a light source. The light sensor senses the ambient luminance and outputs a sensing signal to indicate whether the luminance is greater than a predetermined quantity. The decision device is connected to the light sensor. It receives a switching signal and outputs a lighting signal according to the sensing signal and the switching signal. The light source is coupled to the decision device and is activated whenever the lighting signal demands light.