Bulb Lighting Heat Sink Dual Surface Dissipation

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Solution Overview

Problem

Bulb-type lighting sources with light-emitting elements like LEDs face challenges in heat dispersal due to the restrictive external dimensions and the need for a protective cover, which limits natural cooling and the volume of the heat sink member, leading to reduced luminous efficacy at higher temperatures.

Innovation Solution

A bulb-type lighting source design featuring a bowl-shaped case with a first heat sink member, a mounting substrate in surface contact with the heat sink, a light-emitting unit including a wavelength conversion element, and a second heat sink member that secures a heat dispersal pathway originating from the light-emitting element mounting surface, enhancing heat dissipation through both the top and bottom surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a large-volume heat sink member is placed at the bottom surface to enhance heat dispersal, then heat dispersal characteristics are improved, but the external dimensions of the bulb exceed those of incandescent light bulbs

Engineering Contradiction:

Improveheat dispersal characteristicsVSAvoidexternal dimensions

Core Design Contradiction:

TemperatureVSLength of stationary object

Solution Approach 1:

The patent transitions from a single bottom-surface heat sink to a dual-surface heat dissipation system by adding a heat sink member at the top surface of the mounting substrate, utilizing both vertical surfaces for heat dispersal within the same footprint dimensions

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The heat dissipation function is segmented into two separate heat sink members positioned at opposite surfaces of the mounting substrate, with each heat sink handling thermal loads from different regions (light-emitting unit area vs. peripheral area)

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If a protective cover (globe) is added to cover the mounting substrate, then the bulb can be used in ordinary domestic light fixtures, but natural cooling of the mounting substrate is significantly limited

Engineering Contradiction:

Improvecompatibility with lighting equipmentVSAvoidnatural cooling effect

Core Design Contradiction:

Adaptability or versatilityVSTemperature

Solution Approach 1:

The patent introduces heat sink members as intermediary thermal management components between the light-emitting unit and the ambient environment, enabling effective heat dispersal even when natural convection through the globe is limited

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces reliance on natural convection cooling (passive thermal management) with conduction-based heat sinking through metal heat sink members that provide dedicated thermal pathways to the ambient air

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Illumination intensity

If electrical power input to LED is increased to produce suitable total luminous flux, then luminous output is improved, but heat generated by LED increases leading to temperature rise and drop in luminous efficacy

Engineering Contradiction:

Improvetotal luminous fluxVSAvoidtemperature rise

Core Design Contradiction:

Illumination intensityVSTemperature

Solution Approach 1:

The patent extracts heat from the light-emitting unit by providing dedicated heat sink members at both surfaces of the mounting substrate, creating separate thermal management pathways that remove heat before it can raise the operating temperature of the LED

Inventive Principle:

Principle #2Taking out (Extraction)

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 design achieves better heat dispersal characteristics compared to conventional technologies, inhibiting temperature rise and maintaining luminous efficacy by securing a heat dispersal pathway from the light-emitting element mounting surface, thereby improving the performance of bulb-type lighting sources.

Implementation Method 1

a first heat sink member that closes a mouth of the bowl-shaped case, a mounting substrate that is in surface contact with a front surface of the first heat sink member... a second heat sink member that has a first part in surface contact with a region of the front surface of the mounting substrate... and that has a second part in surface contact with the first heat sink member

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS8337049B2Bulb-type lighting source

Publication Date: 2012.12.25 PANASONIC HOLDINGS CORP

AI summary

A bulb-type lighting source employs a light-emitting element in a structure that facilitates heat dispersal. The lighting source includes a first heat sink member mounted in a bowl shaped case supporting a power supply circuit. A mounting substrate is positioned in surface contact with a surface of the heat sink member and is capable of supporting a light-emitting unit. A globe covers the light-emitting unit to permit light emission. A second heat sink member has a surface in contact with a perimeter of the mounting substrate and offset from the light-emitting unit to provide a second part in surface contact with the first heat member to facilitate the release of heat.