Solid-State Lighting Bulb Stem Carrier Design

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Solution Overview

Problem

Existing SSL light bulbs face challenges in compatibility with conventional GLS production lines, requiring modifications to stem design and assembly processes to achieve robustness and efficient heat transfer while maintaining energy efficiency and long operational lifetime.

Innovation Solution

A light bulb design featuring a stem with a base portion and a tubular carrier that supports SSL devices, where the carrier is directly or indirectly attached to the stem, and the stem is sealed within a gas-filled envelope, allowing for easy production on existing GLS lines with minimal modifications, utilizing a gas mixture like helium and oxygen for improved thermal performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If SSL devices are mounted on a carrier supported by a stem inside a gas-filled envelope, then heat transfer efficiency and operational lifetime are improved, but device complexity and manufacturing difficulty increase compared to conventional GLS bulbs

Engineering Contradiction:
Improveoperational lifetimeVSAvoiddevice complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The light bulb is divided into distinct functional components: a cap for electrical connection, a stem for structural support and gas filling, a carrier for mounting SSL devices, and an envelope for gas containment. This segmentation allows each component to be optimized independently while maintaining compatibility with conventional production lines.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stem serves multiple functions: providing structural support for the carrier, serving as a conduit for gas filling during manufacturing, and acting as a seal between the cap and envelope. This multi-functionality reduces the number of separate components needed while maintaining system robustness.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Strength

If the stem design is modified to include a base portion and tube portion for supporting the carrier, then mechanical robustness is improved, but compatibility with existing GLS production lines deteriorates

Engineering Contradiction:
Improvemechanical robustnessVSAvoidease of manufacture
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The stem design incorporates a flexible transition between the base portion and tube portion, allowing the structure to adapt to slight variations in assembly tolerances while maintaining mechanical strength. This dynamic characteristic enables robust construction without requiring precision manufacturing equipment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The stem exhibits different structural characteristics at different locations: the base portion has a larger diameter for structural support and carrier mounting, while the tube portion has a smaller diameter for gas filling. This local differentiation optimizes both mechanical strength and manufacturability.

Inventive Principle:
Principle #3Local quality

3Temperature

If helium gas is used in the envelope for improved thermal conductivity, then heat transfer from SSL devices is improved, but manufacturing complexity increases due to gas filling requirements

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The stem is designed with a tube portion that remains open during initial assembly, allowing helium gas to be introduced into the envelope before the final sealing operation. This preliminary action simplifies the gas filling process by integrating it into the existing sealing workflow rather than requiring separate equipment.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The tube portion of the stem acts as an intermediary conduit, connecting the external gas filling system to the internal envelope space. This intermediary structure enables controlled gas introduction while maintaining the integrity of the sealed envelope system.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design enables robust construction, efficient heat transfer, and extended operational lifetime by aligning with existing production lines, ensuring compatibility and performance enhancements through the use of a gas-filled envelope and optimized carrier-stem interface.

Implementation Method 1

utilizing a gas mixture like helium and oxygen for improved thermal performance

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3308071B1Light bulb with solid-state lighting devices
Publication Date: 2019.08.07 SIGNIFY HOLDING BV
  • EP3308071B1 patent drawingFigure 1
  • EP3308071B1 patent drawingFigure 2~3
  • EP3308071B1 patent drawingFigure 4~5

AI summary

There is provided a light bulb (1) which comprises: a cap (2) for mechanically and electrically connecting the light bulb (1) to a lamp socket; a light-transmissive envelope (3); a stem (12) arranged inside the envelope (3), the stem (12) including a base portion (13) proximal to the cap (2); and at least one carrier (7) and one or more solid-state lighting devices (6) mounted on the at least one carrier (7) inside the envelope (3). The at least one carrier (7) is supported by the base portion (13) of the stem (12). There is also provided a method for producing a light bulb (1).