Keypad Backlight Luminance Control via Display Feedback
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Solution Overview
Problem
The keypad backlight on electronic devices often exceeds the display luminance, causing distraction and discomfort, especially in dark ambient lighting conditions, due to improved LED and light guide technology that can result in keypad luminance surpassing display luminance.
Innovation Solution
A method and apparatus for adjusting the keypad backlight intensity based on ambient light and display luminance levels, ensuring the backlight luminance does not exceed the display luminance by calculating the difference and applying it to the keypad backlight controller, using a light sensor and processor to adjust the lighting level dynamically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the keypad backlight intensity is increased to improve readability in dark conditions, then the readability is improved, but the distraction from the display increases and viewing comfort decreases
Solution Approach 1:
The system continuously monitors display luminance levels and uses this feedback to dynamically adjust keypad backlight intensity, ensuring it never exceeds display luminance and thereby preventing distraction while maintaining readability
Solution Approach 2:
The invention changes the luminance parameter of the keypad backlight based on ambient light conditions and display content, adjusting it to match display luminance levels to eliminate the harmful effect of excessive brightness
2Illumination intensity
If the keypad backlight is turned on in all conditions to ensure readability, then readability is maintained, but power consumption increases
Solution Approach 1:
The system dynamically adjusts keypad backlight intensity based on real-time conditions: turning it off in bright environments to save power, and activating it only when ambient light conditions require it for readability
Solution Approach 2:
The invention changes the operational state parameter of the backlight from static (always on/off) to dynamic, adjusting intensity based on ambient light sensor readings and display luminance requirements
3Illumination intensity
If improved LED and light guide technology is used to increase keypad luminance, then readability in dark conditions is improved, but the keypad luminance may exceed display luminance causing distraction
Solution Approach 1:
The system uses feedback from display luminance measurements to control keypad backlight intensity, ensuring that even with improved LED technology, the keypad luminance never exceeds display luminance and thus prevents distraction
Solution Approach 2:
The invention applies preliminary control by calculating the maximum safe backlight intensity based on display luminance before activating the backlight, preventing the harmful effect of excessive luminance before it can occur
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 maintains comfortable viewing by ensuring the keypad luminance is equal to or less than the display luminance, reducing power consumption and minimizing distractions, while improving ergonomic comfort.
Implementation Method 1
Mobile electronic handheld devices may include a light sensor for sampling ambient light conditions
Data Source
AI summary
A method and system are set forth for automatically adjusting keypad luminance based on display content. In one embodiment, the method comprises calculating a lighting level based on ambient light; calculating a luminance level of an image on the display; setting a maximum lighting level to the luminance level of the image on the display; and in the event the calculated lighting level exceeds the maximum lighting level then selecting the maximum lighting level, and in the event the calculated lighting level does not exceed the maximum lighting level then selecting the calculated lighting level.