Projector Fan Controller Intermittent Cooling for Light Source

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Solution Overview

Problem

Projectors face challenges in maintaining the reliability of light sources and optical parts during power saving modes, where reduced lamp luminance and altered cooling fan operations can lead to overcooling or increased temperatures, compromising performance and reliability.

Innovation Solution

A projector design that includes a fan controller to operate the cooling fan intermittently when light source luminance is lower than normal, optimizing start and stop timings to maintain optimal temperatures for both the light source and optical parts, and optionally using a second fan to prevent overcooling of the light source.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the cooling fan is driven at the same number of revolutions as in normal operation during power saving mode, then the optical parts are cooled sufficiently, but the light source section becomes overcooled causing vapor condensation and reliability decrease

Engineering Contradiction:

Improvelight source section reliabilityVSAvoidlight source section temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The cooling fan is operated intermittently with periodic on/off cycles instead of continuously. The control unit switches the fan between operating and stopping states based on temperature feedback from the light source section, allowing the temperature to be maintained within a target range while reducing overall cooling action that would cause overcooling and vapor condensation.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

A temperature sensor monitors the light source section temperature and provides feedback to the control unit. The control unit adjusts the cooling fan operation based on this feedback, comparing the detected temperature against target temperature ranges to determine when the fan should operate or stop, thereby preventing both overheating and overcooling.

Inventive Principle:

Principle #23Feedback

2Reliability

If the cooling fan number of revolutions is reduced during power saving mode, then the light source section is prevented from overcooling, but the optical parts temperature increases reducing their performance and reliability

Engineering Contradiction:

Improveoptical parts reliabilityVSAvoidoptical parts temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The cooling fan operates intermittently with periodic on/off cycles rather than continuously at reduced speed. This periodic operation allows the optical parts to be cooled sufficiently during the 'on' periods while avoiding continuous cooling that would overcool the light source section during the 'off' periods.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The cooling system is controlled to provide different cooling levels to different regions. By operating the fan intermittently based on light source section temperature feedback, the system provides intensive cooling when the light source needs it and allows the optical parts to maintain acceptable temperatures through thermal inertia and reduced cooling demand.

Inventive Principle:

Principle #3Local quality

3Temperature

If the cooling fan operates continuously at high speed, then all components are cooled effectively, but power consumption increases and the light source section may be overcooled

Engineering Contradiction:

Improvecomponent temperature controlVSAvoidcooling fan power consumption

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The cooling fan operates intermittently with periodic on/off cycles instead of continuously. This reduces the total operating time of the fan, thereby lowering power consumption while still maintaining adequate cooling of the optical parts through cooling during critical periods when heat generation is highest.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The control unit uses temperature feedback from the light source section to intelligently control fan operation. The fan operates only when the light source section temperature exceeds the upper limit of the target range, avoiding unnecessary continuous operation and reducing power consumption while maintaining effective temperature control.

Inventive Principle:

Principle #23Feedback

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 the reliability of the light source and optical parts by maintaining appropriate temperatures, reducing power consumption, and improving the projector's overall performance in power-saving modes.

Implementation Method 1

a first fan that cools the optical part

Methodology Applied

Scientific EffectForced Convection: Forced Convection

Data Source

PatentUS9298073B2Projector and method for controlling projector

Publication Date: 2016.03.29 SEIKO EPSON CORP

AI summary

A projector includes an optical part including a light source section that outputs light, a light modulator that modulates the light outputted from the light source section based on an image signal, a projection optical section that projects the modulated light from the light modulator, a first fan that cools the optical part, and a fan controller that controls the first fan, and the fan controller operates the first fan intermittently when the light source section outputs light of luminance lower than luminance corresponding to normal image display.