Light-Emitting Device Control Module for Series String Fault Management

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Solution Overview

Problem

Conventional light-emitting modules with series-connected units face significant brightness reduction and potential damage due to voltage drop when malfunctioning units are present, leading to inefficient operation.

Innovation Solution

A light-emitting device with a control module that monitors voltage drops across current control units to identify malfunctioning strings, shorts malfunctioned units, and adjusts DC voltage to prevent damage, allowing flexible operation and maintaining brightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the entire string of light-emitting units is turned off when malfunctioned units reach a predetermined value, then the damage to other units is prevented, but the brightness of the light source is significantly reduced

Engineering Contradiction:
Improveprotection of light-emitting unitsVSAvoidbrightness of light source
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The patent divides the light-emitting string into independently controllable segments. When malfunctioned units are detected, only the affected segment is turned off while other segments continue to operate, preventing total string shutdown and maintaining partial brightness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of turning off the entire string when a threshold of malfunctioned units is reached, the patent applies partial action by selectively shutting down only the affected portion of the string, allowing the majority of functional units to continue operating.

Inventive Principle:
Principle #16Partial or excessive action

2Illumination intensity

If light-emitting units are connected in series to provide uniform light source, then the light distribution is uniform, but voltage drop accumulates and may damage other units when malfunction occurs

Engineering Contradiction:
Improveuniformity of light sourceVSAvoidvoltage stability of light-emitting units
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent segments the series-connected light-emitting string into multiple independently controllable groups. This allows voltage drop from malfunctioned units to be isolated to specific segments, preventing voltage accumulation across the entire string and protecting other units from damage.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If conventional monitoring methods are used to detect malfunctioned units, then the malfunction detection is simple, but the response time and precision are insufficient

Engineering Contradiction:
Improvesimplicity of monitoring systemVSAvoidprecision of malfunction detection
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the control module continuously monitors voltage drops across current control units and automatically adjusts by shorting malfunctioned units based on the detected voltage changes, enabling precise and timely malfunction detection and response.

Inventive Principle:
Principle #23Feedback

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 reduces power consumption and minimizes brightness loss by selectively shorting malfunctioned units and adjusting voltage, thereby enhancing the operational efficiency and longevity of light-emitting modules.

Implementation Method 1

the control module shorts the malfunctioned light-emitting units in the specific string and shorts (x - p + 1) light-emitting units in each of the light-emitting unit strings other than the specific string

Methodology Applied
Scientific EffectElectrical shorting: Conduction (electrical)

Implementation Method 2

Solid state light-emitting units, such as a light-emitting diode (LED)

Methodology Applied
Scientific EffectLight-emitting diode effect: Light Emitting Diode

Implementation Method 3

light-emitting units connected in series

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2763503B1Light-emitting device and control method of the same
Publication Date: 2018.12.12 DELTA ELECTRONICS INC(CN)
  • EP2763503B1 patent drawingFigure 1A
  • EP2763503B1 patent drawingFigure 1B
  • EP2763503B1 patent drawingFigure 2

AI summary

A light-emitting device control method is provided. The light-emitting device control method comprises the steps outlined below. A light-emitting module of a light-emitting device having light-emitting unit string each having light-emitting units connected in series is operated. One end of each light-emitting unit strings receives a same DC voltage. A voltage drop value across each current control units connected in series to at least one of the light-emitting unit strings is retrieved to further determine whether the light-emitting unit of each of the light-emitting unit strings malfunctions. When x light-emitting units of a specific string malfunction and x is larger than or equal to a malfunction threshold value p, the x malfunctioned light-emitting units are shorted and (x - p + 1) light-emitting units in each of the light-emitting unit strings other than the specific string are shorted. The DC voltage received by each of the light-emitting units is decreased.