Forklift Projector Free-Form Lens Bundles Light

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing warning devices for industrial trucks, such as rotating and flashing lights, suffer from habituation and luminous flux losses due to shading in non-round motifs, leading to reduced brightness and energy inefficiency in projecting pictorial warning symbols onto roadways.

Innovation Solution

Incorporating a free-form lens between the light source and the image template to bundle the luminous flux onto translucent areas, minimizing shading and increasing light output, along with passive cooling and a condenser to enhance light distribution and reduce beam divergence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a conventional projector with a transilluminated image template is used to project warning symbols, then the warning symbol can be projected onto the roadway, but there is very large luminous flux loss due to shading in non-round motifs, resulting in reduced brightness and low luminous efficacy

Engineering Contradiction:
Improvebrightness of projected warning symbolVSAvoidluminous flux loss
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent segments the light path by introducing a beam shaping element that divides and redirects luminous flux into multiple paths, allowing light to reach previously shaded areas of the image template without direct line-of-sight from the light source

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The beam shaping element acts as an intermediary optical component between the light source and image template, manipulating the luminous flux distribution to eliminate shading effects while maintaining the integrity of the projected warning symbol

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If rotating or flashing lights are used as warning devices, then the warning area can be covered, but habituation effect occurs and the warning is not limited to specific danger areas, leading to reduced effectiveness

Engineering Contradiction:
Improvehabituation effect and reduced warning effectivenessVSAvoidvisibility of warning
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent applies local quality by projecting light only in the specific direction of travel onto the roadway surface, creating a localized warning effect precisely where needed rather than omnidirectional illumination that causes habituation

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transitions from traditional vertical or horizontal light emission to projecting light onto the two-dimensional roadway surface in the direction of travel, adding a spatial dimension that grounds the warning in the specific hazard zone

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

3Use of energy by moving object

If the light source radiates luminous flux over the entire area of the image template, then the complete image can be illuminated, but the shaded areas absorb excess light, causing high luminous flux losses and reduced energy efficiency

Engineering Contradiction:
Improveenergy efficiency of projectorVSAvoidlight output to translucent area
Core Design Contradiction:
Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent changes the spatial distribution parameters of luminous flux using the beam shaping element, transforming the light pattern from uniform omnidirectional radiation to a concentrated, directionally-controlled illumination that matches the translucent areas of the image template

Inventive Principle:
Principle #35Parameter changes

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 solution results in a brighter and more energy-efficient projection of warning symbols with reduced luminous flux losses, providing effective and clear visual warnings without the need for additional cooling fans, even in oblique projections.

Implementation Method 1

the projector having a free-form lens arranged between the light source and the original image, the free-form lens being designed in such a way that the luminous flux of the light source is bundled onto the translucent area of the original image

Methodology Applied
Scientific EffectLight refraction and focusing: Lens

Implementation Method 2

along with passive cooling and a condenser to enhance light distribution and reduce beam divergence

Methodology Applied
Scientific EffectLight condensation and collimation: Lens

Implementation Method 3

Particular advantages result if the projector has a housing on which a heat sink with cooling ribs is arranged adjacent to the light source

Methodology Applied
Scientific EffectThermal conduction and convection: Heat Sink

Data Source

PatentEP3279135B1Warning device for an industrial truck
Publication Date: 2019.03.20 LINDE MATERIAL HANDLING GMBH
  • EP3279135B1 patent drawingFigure 1
  • EP3279135B1 patent drawingFigure 2~5
  • EP3279135B1 patent drawingFigure 3

AI summary

The invention relates to a warning device for a forklift truck which, arranged on the forklift truck, projects a pictorial indicator symbol, in particular a pictorial warning symbol, onto a roadway, wherein the warning device is designed as a projector (30) which has a light source (32) which emits a luminous flux and an image template (35) of the indicator symbol (20) to be projected, which is translucent by the luminous flux generated by the light source (32).In the projector (30) according to the invention, the image template (35) has at least one area (40) that transmits light to the luminous flux of the light source (32) and an area (41) that shades the luminous flux of the light source (32), and the projector (30) has a free-form lens (34) arranged between the light source (32) and the image template (35), wherein the free-form lens (34) is designed such that the luminous flux of the light source (32) is focused onto the transparent area (40) of the image template (35).