Projection Apparatus Circuit Board Cooling via Vertical Air Flow

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Solution Overview

Problem

Conventional image projection apparatuses face challenges in reducing noise and size while effectively cooling the power supply and drive circuit boards, particularly when reducing the rotation speed of fans or the number of fans, as this leads to inadequate air flow and potential overheating.

Innovation Solution

The apparatus employs a unique cooling mechanism where the power supply and drive circuit boards are strategically positioned to maximize air flow, using a concave mirror's tilted placement to create a large gap for efficient air circulation, and incorporates a dual-board cooling system with heat sinks to enhance cooling efficiency, even with reduced fan speed or number.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If the rotation speed of the fan is reduced or the number of fans is reduced, then noise is reduced, but the cooling effect on the power supply circuit board and ballast board deteriorates

Engineering Contradiction:
ImprovenoiseVSAvoidcooling effect
Core Design Contradiction:
Object-generated harmful factorsVSTemperature

Solution Approach 1:

The patent introduces a vertical air flow path dimension by positioning the power supply circuit board and ballast board at different heights, allowing air to flow vertically between them. This dimensional arrangement creates a natural convection path that enhances cooling without requiring increased fan speed or additional fans, thus maintaining low noise levels while improving heat dissipation efficiency.

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

Solution Approach 2:

The patent uses air as an intermediary cooling medium that flows through the gap between the power supply circuit board and ballast board. By strategically positioning these components to create an optimal air flow path, the system leverages natural convection and air flow to transfer heat away from the boards, achieving effective cooling with minimal fan intervention and reduced noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If the size of the air flow path is increased, then the cooling effect on the power supply circuit board and ballast board is improved, but the apparatus size increases

Engineering Contradiction:
Improvecooling effectVSAvoidapparatus size
Core Design Contradiction:
TemperatureVSVolume of moving object

Solution Approach 1:

The patent utilizes the vertical dimension within the existing apparatus footprint to create an effective air flow path. By arranging the power supply circuit board and ballast board at different vertical levels, the system establishes a three-dimensional cooling channel that maximizes heat dissipation efficiency without expanding the horizontal footprint of the device, thus maintaining a compact overall size.

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

Solution Approach 2:

The patent nests the cooling air flow path within the existing structural space between the power supply circuit board and ballast board. By positioning these components in a nested configuration where air can flow through the gap between them, the system creates an efficient cooling pathway that utilizes otherwise wasted internal space, achieving improved cooling without increasing the external dimensions of the apparatus.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Temperature

If the air flow path size is increased to improve cooling, then the power supply circuit board and ballast board are cooled effectively, but the number of fans must be increased or their speed increased

Engineering Contradiction:
Improvecooling effectVSAvoidnumber of fans
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent enables the system to cool itself by creating a natural air convection path between the power supply circuit board and ballast board. The strategic positioning of these components allows air to flow through the gap, carrying heat away from the boards through natural convection and pressure differentials, thereby achieving effective cooling without requiring additional fans or increased fan speed, and maintaining system simplicity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent introduces a vertical air flow dimension by positioning components at different heights, creating a natural convection path that eliminates the need for additional cooling fans. This spatial arrangement allows hot air to rise and be replaced by cooler air, establishing a self-sustaining cooling cycle that improves heat dissipation without increasing device complexity or fan requirements.

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

This approach effectively cools the circuit boards, reduces noise, and maintains a compact size by optimizing air flow and heat dissipation, ensuring reliable operation and portability.

Implementation Method 1

a first board cooling flow path that guides air flow to cool the power supply circuit board and a second board cooling flow path that guides air flow to cool the ballast board

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

Heat Sink

Methodology Applied
Scientific EffectThermal Radiation: Thermal Radiation

Implementation Method 3

dual-board cooling system with heat sinks to enhance cooling efficiency

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Data Source

PatentEP3141948B1Image projection apparatus
Publication Date: 2019.06.19 RICOH CO LTD
  • EP3141948B1 patent drawingFigure 1
  • EP3141948B1 patent drawingFigure 2A~2C
  • EP3141948B1 patent drawingFigure 3A~3B

AI summary

An image projection apparatus includes: a light source (162a); a projection optical unit (2) including a concave mirror (5) and configured to guide a projection image on a projection surface (S); an air blower (7) configured to generate a flow of air in a main body casing (14); a power supply circuit board (80a) configured to supply power to an electric component in the main body casing; and a light source drive circuit board (12a) configured to drive the light source (5). At least one of the power supply circuit board (80a) and the light source drive circuit board (12a) is fixed on a facing surface (14b) facing a rear side of the concave mirror (5), of the main body casing (14).