Projector Heat Sink Positioning for LED Cooling

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Solution Overview

Problem

Existing projection apparatuses face inefficiencies in heat dissipation, particularly affecting the brightness of LEDs due to inadequate cooling of blue LEDs, leading to overheating and increased noise when trying to improve brightness by increasing fan speed.

Innovation Solution

A projection apparatus design with a heat dissipation module connected to light sources, where heat sinks are located close to air inlets, allowing direct cooling airflow to reduce internal temperatures without increasing noise by optimizing airflow paths and heat sink placement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the blue LED heat sink is located between the optical engine module and electromagnetic shielding casing, then the structure is compact, but the heat sink is in a dead zone of the flow field where cooling airflow does not pass through, resulting in poor heat dissipation

Engineering Contradiction:
Improvecompact structureVSAvoidheat dissipation efficiency
Core Design Contradiction:
Volume of moving objectVSTemperature

Solution Approach 1:

The patent repositions the blue LED heat sink from a horizontal arrangement (between optical engine and shielding casing) to a vertical arrangement adjacent to the air outlet. This spatial reconfiguration moves the heat sink into the main cooling airflow path, allowing effective heat dissipation while preserving compact structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If the fan rotating speed is increased to improve cooling airflow, then the temperature of LEDs is decreased, but the noise value of the whole projection apparatus increases

Engineering Contradiction:
ImproveLED temperatureVSAvoidnoise
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent pre-cools the cooling airflow by positioning heat sinks (particularly the blue LED heat sink) adjacent to the air outlet where the airflow is already cool and fast-moving. This preliminary cooling action reduces LED temperatures before they generate excessive heat, eliminating the need to increase fan speed and thus avoiding noise generation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cooling airflow serves itself by naturally passing through the repositioned heat sinks located in the high-velocity airflow region near the air outlet. The system utilizes the existing airflow dynamics without requiring additional mechanical energy input, achieving effective cooling without increased fan noise.

Inventive Principle:
Principle #25Self-service

3Volume of stationary object

If heat sinks are positioned away from air inlets, then the optical engine module has sufficient space, but the cooling airflow does not effectively cool the light sources

Engineering Contradiction:
Improvespace for optical engineVSAvoidlight source temperature
Core Design Contradiction:
Volume of stationary objectVSTemperature

Solution Approach 1:

Instead of positioning heat sinks only near air inlets (horizontal cooling approach), the patent utilizes the vertical dimension by placing heat sinks adjacent to the air outlet. This creates a three-dimensional cooling strategy where the blue LED heat sink benefits from the high-velocity upward airflow at the outlet, effectively cooling light sources while preserving optical engine space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 achieves effective heat dissipation, maintaining higher optical efficiency and brightness of LEDs without the noise associated with increased fan speeds, ensuring better performance and user experience.

Implementation Method 1

the heat dissipation module includes a plurality of heat sinks, and the heat sinks are located close to the air inlets, respectively

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

When a cooling airflow enters the casing, the cooling airflow first flows through the heat sink of the red LED, and then flows through the heat sink of the green LED

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3557321B1Cooling of projector
Publication Date: 2021.11.24 CORETRONIC CORPORATION
  • EP3557321B1 patent drawingFigure 1
  • EP3557321B1 patent drawingFigure 2
  • EP3557321B1 patent drawingFigure 3

AI summary

A projection apparatus includes a casing, a light source module, an optical engine module, a heat dissipation module and a projection lens. The casing has multiple air inlets and an air outlet. The light source module is disposed in the casing, and is configured to provide an illumination beam, wherein the light source module includes multiple light sources. The optical engine module is disposed in the casing, and is located on a transmission path of the illumination beam, and is configured to convert the illumination beam into an image beam. The heat dissipation module is disposed in the casing, and is connected to the light sources, where the heat dissipation module includes multiple heat sinks located close to the air inlets, respectively. The projection lens is disposed in the casing, and is connected to the optical engine module, and is configured to project the image beam out of the casing.