Projector Gobo Light Efficiency via LED Additive Mixing

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Solution Overview

Problem

Existing headlamps for generating lighting effects using mercury vapor lamps have low efficiency, especially for colored light effects, due to strong light resistance requiring cooling, which adds space, cost, weight, and noise.

Innovation Solution

Combining an additive color mixer, such as a 3-color LED lamp, with a subtractive color mixer using coated glass gobos, allowing independent control of individual LEDs to produce a wide range of colors, including intermediate colors, and achieving efficient light output without the need for cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a mercury vapor lamp with a gobo element is used to generate colored light effects, then the light efficiency is very low (only 10% of light intensity available), but the gobo element can be made strong to withstand light resistance

Engineering Contradiction:

Improvelight efficiencyVSAvoidgobo element strength

Core Design Contradiction:

Loss of energyVSStrength

Solution Approach 1:

The patent changes the light source parameters from mercury vapor lamp to LED, fundamentally altering the spectral characteristics and efficiency. LEDs emit light more efficiently and allow the gobo element to operate without excessive heat resistance requirements, resolving the contradiction between light efficiency and gobo strength requirements

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/thermal system (mercury vapor lamp generating intense heat requiring strong gobo elements) with an electrical/optical system (LEDs generating light with minimal heat), eliminating the need for strong heat-resistant gobo construction

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a strong gobo element is used to withstand light resistance, then the gobo can handle high intensity light, but additional cooling fans are required which generate noise and require additional space

Engineering Contradiction:

Improvegobo element durabilityVSAvoidcooling system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the cooling system (fans) entirely by replacing the high-heat mercury vapor lamp with low-heat LEDs. This eliminates the need for cooling infrastructure, reducing device complexity and noise while maintaining gobo durability through reduced thermal stress

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the harmful effect of heat generation by using LEDs that inherently produce minimal heat compared to mercury vapor lamps. This turns the previously harmful thermal environment into a beneficial low-heat operation that protects the gobo element and eliminates cooling requirements

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Adaptability or versatility

If a mercury vapor lamp is used as a white light source with a gobo element, then various color effects can be produced, but the efficiency is very low especially for colored light effects

Engineering Contradiction:

Improvecolor effect varietyVSAvoidlight generation efficiency

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent segments the single white light source into multiple colored LED sources (red, green, blue). Each LED emits its specific color directly, eliminating the need for a gobo to filter out unwanted wavelengths. This segmentation maintains color versatility while dramatically improving efficiency by matching the LED emission spectrum to the desired output color

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent inverts the traditional approach by instead of using a white light source and filtering with a gobo, it uses colored light sources that directly emit the desired colors. This inversion eliminates the inherent efficiency loss of subtractive color mixing while preserving full color versatility

Inventive Principle:

Principle #13The other way round (Inversion)

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 combination significantly increases light efficiency, allows for precise control of color effects, and reduces thermal issues, enabling high-lumen output without excessive heat generation.

Implementation Method 1

The light source is formed by an additive color mixer, in particular a 3-color LED lamp

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

The gobo elements are formed to filter out a particular color spectrum from the white light emitted from the mercury steam lamp

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP2487405B1Projector with gobo and method for operating the projector

Publication Date: 2021.03.17 GLP GERMAN LIGHT PRODS

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AI summary

The headlamp (14) has Scheinwerfer (14) mit folgenden Merkmalen:an additive color mixer (10) that is used as a light source, and a subtractive color mixer (12) that are accommodated within housing (16). The additive color mixer is comprised of two lamps or three LEDs which are designed to emit light rays in different colors. The light intensities of the two lamps are independently controlled. The LEDs are configured such that the LEDs are combined to define a color space. The LEDs are red, green and blue LEDs. An independent claim is included for method for operating headlamp.