PWM Luminous Element Illumination Modulation for Smooth Brightness Transitions
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Solution Overview
Problem
Abrupt changes in illumination levels of luminous elements, such as LEDs, can be uncomfortable for consumers, and existing methods do not effectively provide a smooth and pleasant transition in operational status communication.
Innovation Solution
The use of Pulse-Width-Modulation (PWM) signals with a human-eye-compensation-formula and harmonic-natural-sine-function to modulate the illumination level of luminous elements, ensuring a sinusoidal perception by the human eye, allowing for gradual and pleasing changes in brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the LED illumination level is adjusted by switching on/off or blinking, then the operational status is clearly communicated, but the abrupt change in illumination level causes discomfort to consumers
Solution Approach 1:
The patent applies periodic action by using PWM signals to modulate the LED illumination level. Instead of abrupt on/off switching, the illumination is adjusted through periodic pulses with varying duty cycles, creating a smooth transitional effect that communicates operational status while avoiding consumer discomfort from sudden brightness changes.
Solution Approach 2:
The patent implements dynamics by making the illumination level adjustable and continuously variable through PWM control. The system dynamically transitions between different brightness levels rather than maintaining fixed states, allowing for smooth morphing between operational status indications while maintaining clear communication.
2Device complexity
If a linear PWM signal is used to control LED brightness, then the control is simple, but the human eye perceives the brightness change as nonlinear due to nonlinear sensitivity
Solution Approach 1:
The patent applies parameter changes by modifying the PWM signal characteristics based on human eye sensitivity. Instead of using a simple linear PWM signal, the system adjusts the pulse width parameters according to a nonlinear compensation formula that accounts for human perception, achieving perceived linearity while maintaining control effectiveness.
Solution Approach 2:
The patent implements feedback by incorporating human eye sensitivity characteristics into the control system. The PWM signal generation uses a compensation formula that effectively feeds back the nonlinear perception characteristics, adjusting the control parameters to match human visual response and achieve perceived linear brightness transitions.
Data Source
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AI summary
An illumination level of a luminous element of a user interface for an electrical device is controlled by a processor driving the luminous element with a pulse-width-modulated (PWM) or other type of control signal that is calculated based on a) a signal corresponding to a desired time-varying illumination level of the luminous element to be perceived by a human observer and b) a nonlinear sensitivity relationship between an actual illumination level and a resulting illumination level perceived by a human eye, wherein the corresponding signal comprises an increasing sinusoidal-based ramp function and a decreasing sinusoidal-based ramp function.