LED Light with Photoluminescent Phosphor for Flicker Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED lights face significant challenges in reducing stroboscopic flickering, particularly in compact designs, due to the limitations of electronic smoothing capacitors and the complexity and cost of phosphorescent materials, which hinder miniaturization and increase manufacturing effort and failure rates.
Innovation Solution
The integration of a photoluminescent phosphor coating on the LED module for optical smoothing, combined with electronic components in the LED driver for current smoothing, including a rectifier, small capacitors, and frequency modulation, to synergistically reduce flickering without increasing size or cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If large smoothing capacitors are used to effectively avoid current/voltage fluctuations, then flickering is reduced, but installation space increases and manufacturing complexity increases
Solution Approach 1:
The patent combines optical smoothing (photoluminescent phosphor) and electronic smoothing (small capacitors) into a hybrid system. The phosphor layer provides optical energy storage and time-delayed emission, while small electronic capacitors supplement the smoothing effect, achieving effective flicker reduction without requiring large capacitor volumes.
Solution Approach 2:
The photoluminescent phosphor acts as an intermediary between the LED light source and the viewer. It absorbs LED light energy during the illumination phase and emits stored energy during the off-phase, mediating the flicker effect optically before it reaches the observer, thereby reducing perceived flickering without large electronic components.
2Reliability
If multiple light buffers with different relaxation times are used to optimize flicker reduction, then flicker reduction is improved, but material costs increase and installation space increases
Solution Approach 1:
Instead of using multiple phosphor layers with different properties throughout the entire structure, the patent applies a single photoluminescent phosphor layer with specific relaxation characteristics at the critical location (near the LED). This localized approach provides sufficient optical smoothing without the complexity and cost of multiple materials.
Solution Approach 2:
The patent replaces expensive rare-earth phosphor materials with more cost-effective photoluminescent materials that achieve the required smoothing effect. By using affordable materials in a simplified single-layer configuration combined with small electronic capacitors, the solution reduces both material costs and manufacturing complexity while maintaining effective flicker reduction.
3Reliability
If electrolytic capacitors are used for smoothing, then capacitance is achieved, but service life decreases and gaseous emission occurs
Solution Approach 1:
The patent replaces traditional electrolytic capacitors with solid-state ceramic capacitors. While ceramic capacitors have different characteristics, they eliminate the gaseous emission problem and extend service life by removing the electrolyte that degrades over time. The design uses small capacitance values (1-5 μF) that are sufficient when combined with the optical smoothing effect of the phosphor layer.
4Ease of manufacture
If chip-on-board assembly is used for LED mounting, then manufacturing is simplified, but integration of smoothing capacitors requires additional SMD soldering or PTH mounting processes
Solution Approach 1:
The patent merges the optical smoothing function (phosphor layer) and electronic smoothing function (small capacitors) into a unified design that works synergistically. The phosphor layer is applied directly to the LED module during standard manufacturing, and small capacitors are integrated into the driver circuit, eliminating the need for separate large-capacitor mounting processes while maintaining effective flicker reduction.
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 approach effectively reduces stroboscopic flickering to SVM values below 0.4, achieving a compact, cost-effective, and reliable LED light with minimal additional structural costs and dimensions.
Implementation Method 1
an LED module which is coated with a photoluminescent phosphor, which is configured for absorption of light energy from the LEDs and time-delayed emission of the stored light energy
Implementation Method 2
the LED driver has at least one smoothing capacitor parallel-connected to the LEDs
Implementation Method 3
rectifiers with smoothing capacitors are usually required for suppression or reduction of the flickering. This electronic unit is designated as a 'driver' or also an 'electronic ballast' and converts the AC output voltage into a direct current
Data Source
AI summary
An LED light with an LED module which has one or more LEDs and an LED driver for power supply to the LEDs. The LED module is at least partially coated with a photoluminescent phosphor, which is configured for absorption of light energy from the LEDs and time-delayed emission of the stored light energy, and the LED driver has at least one electronic component for smoothing the current to be output to the LEDs.