LED Control System with Unit Activation Modules for Output Consistency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED-based lighting systems face challenges in achieving consistent light emission characteristics due to variations in LED manufacturing and assembly, leading to inefficiencies and increased costs in applications requiring uniform light output.
Innovation Solution
A light-emitting element control system comprising a series connection of LEE units with unit activation modules, a control module, and a converting module, which generates and adapts unit activation control signals to compensate for operational variations, ensuring consistent output and efficient power management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If close binning or matching of individual nominally equal LEDs is performed, then light emission consistency is improved, but manufacturing cost increases substantially
Solution Approach 1:
The system segments the LED array into multiple independently controllable groups or individual LEDs, each with its own control circuit. This allows separate adjustment of each LED's output to compensate for manufacturing variations without requiring expensive pre-binning, as each LED can be individually calibrated and controlled to achieve uniform overall output.
Solution Approach 2:
The system changes the operating parameters (current, voltage, pulse width) of individual LEDs dynamically through digital control circuits. By adjusting these parameters, the system compensates for manufacturing variations in LED characteristics, enabling consistent light output without requiring precise initial sorting or matching of LEDs.
2Device complexity
If simple LED driver circuits with current sources are used, then device complexity and cost are reduced, but energy efficiency and operational flexibility are limited
Solution Approach 1:
The system transitions from static current sources to dynamic, digitally controlled driving circuits that can adaptively adjust operating parameters in real-time. This allows the system to optimize energy efficiency by adjusting LED operating points based on actual performance and requirements, while maintaining relatively simple circuit implementations through the use of standard digital control components.
Solution Approach 2:
The system incorporates feedback mechanisms where the actual light output or electrical characteristics of LEDs are monitored and used to adjust driving parameters. This feedback control enables improved energy efficiency by optimizing power delivery to match actual LED performance and requirements, while using relatively simple control circuits to implement the feedback loops.
3Ease of manufacture
If variations in LED output are allowed, then manufacturing cost is reduced, but light emission uniformity deteriorates
Solution Approach 1:
The system performs preliminary characterization and calibration of each LED during or after assembly, storing individual correction factors or parameters in memory. This preliminary action allows the use of LEDs with manufacturing variations while ensuring uniform output, as the system has already prepared the necessary compensation data without requiring expensive pre-binning processes.
Solution Approach 2:
The system dynamically changes operating parameters for individual LEDs based on their specific characteristics and desired output levels. By adjusting current, voltage, or pulse width parameters, the system compensates for manufacturing variations in real-time, maintaining light emission uniformity while allowing the use of LEDs with broader manufacturing tolerances and lower cost.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A light-emitting element control system is described comprising a series connection of one or more LEE units, each comprising one or more LEEs and a unit activation module. The unit activation module associated with a LEE unit is configured to controllably activate, in response to a unit activation control signal, the one or more LEEs in that unit. A control module is operatively coupled to each of the unit activation modules and configured to provide the unit activation control signals thereto. A converting module is operatively coupled to the series connection of LEE units, adapted for connection to a source of power and configured to provide a drive current to the LEE units.