LED Lighting Device Light Decay Compensation
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Solution Overview
Problem
Current LED lighting devices with light decay compensation functions face issues such as increased power consumption and ineffective compensation for light decay caused by changes in light cover transmittance, leading to inefficient energy use and reduced service life.
Innovation Solution
A lighting device comprising multiple light-emitting modules, a memory module, a driving module, an illumination detecting module, and a control module that saves initial illumination values, detects current illumination, and adjusts driving current to compensate for light decay, while switching to other modules when maximal current is reached to prevent power increase and extend service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the driving current is increased to compensate for light decay, then the illumination is maintained, but the power consumption increases
Solution Approach 1:
The lighting device is divided into multiple light-emitting modules (first, second, third modules) that can be independently controlled. When one module reaches its maximum driving current, the system switches to another module, distributing the compensation burden across multiple segments rather than overloading a single module, thus maintaining illumination without continuously increasing power consumption of a single module.
Solution Approach 2:
The system implements periodic switching between light-emitting modules during light decay compensation. When the first module reaches maximum current, the system switches to the second module, and later to the third module, creating a periodic action pattern that maintains overall illumination while managing power consumption through temporal distribution of the compensation load.
2Illumination intensity
If the driving current is increased to compensate for light decay, then the illumination is maintained, but the service life is reduced
Solution Approach 1:
By segmenting the lighting system into multiple independent light-emitting modules, the patent distributes the operational stress across multiple components. Each module operates at or near its maximum current only when needed for compensation, while other modules remain at lower stress levels, thereby extending the overall service life of the lighting device.
Solution Approach 2:
The periodic switching between multiple light-emitting modules allows each module to have periods of high-intensity operation (when providing compensation) and periods of lower operation (when not actively compensating). This temporal distribution reduces cumulative stress on individual modules, extending their service life while maintaining overall illumination levels.
3Device complexity
If the illumination detection is performed inside the light cover, then the detection is simple, but the transmittance changes over time affecting accuracy
Solution Approach 1:
The patent uses an illuminance sensor that detects ambient light as an intermediary measurement. Instead of directly measuring the light output of the LEDs (which would be affected by transmittance changes), the system measures the resulting illumination effect on a target surface. This intermediary measurement approach compensates for transmittance variations by measuring the actual light delivery rather than the light source output.
Solution Approach 2:
The system implements a feedback mechanism where the illuminance sensor continuously monitors the actual illumination level, and the control module adjusts the driving current of light-emitting modules based on this feedback. The feedback loop compares the detected illumination with target values and dynamically compensates for variations, including those caused by light cover transmittance changes, thereby maintaining measurement accuracy.
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
The solution effectively maintains constant illumination, reduces power consumption, and extends the service life of LED lighting devices by compensating for light decay and adapting to changes in light cover transmittance, ensuring energy efficiency and user satisfaction.
Implementation Method 1
an illumination detecting module and a control module... The illumination detecting module detects the current illumination value of a target position
Data Source
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AI summary
A lighting device (1) having light decay compensation function includes a plurality of light-emitting modules (15), a memory module (12), a driving module (14), an illumination detecting module (13) and a control module (11). The memory module (12) saves the initial illumination value of a preselected position, and there is a preselected distance between the preselected position and the light-emitting modules (15). The driving module (14) generates a driving current to drive one of the light-emitting modules (15). The illumination detecting module (13) detects the current illumination value of a target position and there is the preselected distance between the target position and the light-emitting modules (15). The control module (11) receives the current illumination value and executes a light decay compensation mode. The control module (11) compares the initial illumination value with the current illumination value to obtain a light decay value and increases the driving current to increase the current illumination value in order to compensate for the light decay value.