Integrated SSLS Control Circuit for Current Limiting

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Solution Overview

Problem

Modern solid-state lighting sources (SSLS) like LEDs face efficiency drops due to low current densities and high current densities, leading to parasitic recombination processes and reliability issues, as existing electronic circuits for current control introduce parasitic parameters and transients.

Innovation Solution

An integrated SSLS control circuit with field-effect transistors and diodes is used to limit current within a predetermined range by turning on SSLSs sequentially based on saturation current, maintaining optimal operating conditions and preventing efficiency droop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If external electronic circuits are used to control operating current, then current control capability is improved, but parasitic circuit parameters increase switching time and generate unwanted transients

Engineering Contradiction:

Improvecurrent control capabilityVSAvoidsystem reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The control circuit is integrated directly into the SSLS device structure, merging the light-generating function and current control function into a single unified device. This eliminates the need for separate external control circuits and their connecting wiring, thereby removing parasitic circuit parameters and unwanted transients while maintaining current control capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The SSLS device structure is designed to perform multiple functions: light generation and current control. By incorporating control circuitry within the same device structure that generates light, the system achieves multi-functionality without requiring additional separate components, thus improving reliability while maintaining operational control.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Ease of operation

If external electronic circuits are used to control operating current, then current control capability is improved, but temperature stability deteriorates

Engineering Contradiction:

Improvecurrent control capabilityVSAvoidtemperature stability

Core Design Contradiction:

Ease of operationVSTemperature

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

3Power

If operating current density is increased to improve optical power output, then power output is improved, but efficiency droop occurs due to temperature increases and electron leakage

Engineering Contradiction:

Improveoptical power outputVSAvoidefficiency droop

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The integrated control circuit continuously monitors the operating current and provides feedback control to maintain current within the optimal range. This feedback mechanism prevents current density from exceeding levels that cause efficiency droop, while still enabling high optical power output through coordinated operation of multiple SSLS elements.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system divides the total optical power output requirement across multiple SSLS elements operating in parallel or series combinations. Each element operates at optimized current density levels within its optimal range, avoiding efficiency droop while collectively achieving high total power output through the coordinated operation of segmented elements.

Inventive Principle:

Principle #1Segmentation

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 ensures stable operation within optimal current ranges, enhancing efficiency and reliability by preventing low and high current density issues, thus maintaining high optical power output.

Implementation Method 1

a plurality of field-effect transistor activation components (e.g., diodes) configured to activate the plurality of field-effect transistors

Methodology Applied

Scientific EffectField-effect transistor activation:

Implementation Method 2

light generating structure formed between the electron supply layer and the hole supply layer

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS10178726B2Solid-state lighting structure with integrated control

Publication Date: 2019.01.08 SENSOR ELECTRONIC TECHNOLOGY INC

AI summary

A solid-state light source (SSLS) structure with integrated control. In one embodiment, a SSLS control circuit can be integrated with a SSLS structure formed from a multiple of SSLSs. The SSLS control circuit controls the total operating current of the SSLS structure to within a predetermined total operating current limit by selectively limiting the current in individual SSLSs or in groups of SSLSs as each are turned on according to a sequential order. The SSLS control circuit limits the current in each of the individual SSLSs or groups of SSLSs as function of the saturation current of the SSLSs. In one embodiment, the individual SSLSs or groups of SSLSs has a turn on voltage corresponding to a voltage causing a preceding SSLS or group of SSLSs in the sequential order to saturate current.