Movable Lens Illumination Device for Uniform LED Light Bundling

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Solution Overview

Problem

Conventional lighting devices with extended light sources suffer from non-uniform light intensity distribution due to the imaging of the light source structure, leading to dark stripes and reduced luminous intensity in the center of the light beam cone, and adjusting the lens position to improve this results in either visible light source structures or decreased intensity.

Innovation Solution

A lighting device featuring an elongated light source, a conical reflector, and a displaceable lens with its focal point positioned behind the imaginary tip of the reflector, ensuring uniform light intensity distribution and efficient bundling of light by mimicking the light source as a spherical wave, allowing for adjustable opening angle of the light cone without reducing luminous flux.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the lens is positioned close to the light source to improve light bundling, then the light cone opening angle is reduced, but the structure of the extended light source becomes visible in the light beam cone

Engineering Contradiction:
Improvelight bundling efficiencyVSAvoiduniformity of light intensity distribution
Core Design Contradiction:
ProductivityVSIllumination intensity

Solution Approach 1:

The conical reflector acts as an intermediary between the extended light source and the lens. It transforms the structured emission from multiple LED chips into a more uniform spherical wave pattern, allowing the lens to bundle light effectively without imaging the discrete LED structures in the far field

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent transitions from considering only the one-dimensional positioning of the lens to incorporating the three-dimensional geometry of the conical reflector. By positioning the lens at a specific distance where the focal point aligns with the reflector tip, the system exploits the radial symmetry of the conical geometry to achieve uniform light distribution while maintaining efficient bundling

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

2Adaptability or versatility

If the lens is displaced to adjust the light cone opening angle, then the opening angle is changed, but the luminous intensity of the light beam cone decreases significantly

Engineering Contradiction:
Improveadjustability of light cone opening angleVSAvoidluminous intensity of light beam cone
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent implements a movable lens that can be displaced along the optical axis to dynamically adjust the light cone opening angle. The lens position is controlled within a predetermined range to optimize between beam spreading and intensity maintenance, allowing adaptive adjustment without significant intensity loss

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the positional parameter of the lens relative to the reflector and light source. By adjusting the lens position, the focal point location changes, which directly controls the opening angle of the light cone while the conical reflector geometry ensures luminous flux consistency across different positions

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If an extended light source with multiple LEDs is used to increase total luminous flux, then the overall light output is improved, but dark stripes appear between individual emission surfaces in the light beam cone

Engineering Contradiction:
Improvetotal luminous fluxVSAvoiduniformity of light intensity distribution
Core Design Contradiction:
Quantity of substanceVSIllumination intensity

Solution Approach 1:

The conical reflector merges the light from multiple discrete LED emission surfaces into a unified spherical wave pattern. The reflective conical geometry combines rays from different LED chips and angles, creating a homogeneous light distribution that eliminates the dark stripes between individual LED emissions in the far field

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent applies different optical paths for different regions of the light source. The conical reflector provides angle-dependent reflection that redistributes light from high-intensity LED regions to low-intensity areas, creating uniform local quality across the entire light beam cone

Inventive Principle:
Principle #3Local quality

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 achieves a light beam cone with uniform light intensity distribution and high luminous flux, effectively blurring the light source structures and maintaining luminous flux consistency across different lens positions, optimizing light bundling and mixing.

Implementation Method 1

a reflector which encloses the light source and forms a light beam cone with an opening angle of 60° to 120° with respect to an optical axis by reflecting the light emitted by the light source

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

a lens for bundling the emitted light, wherein the lens is arranged to be displaceable along an optical axis of the lighting device

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2233820B1Illumination device with a light source comprising several LED chips, a conical reflector and a movable lens
Publication Date: 2016.09.28 JB LIGHTING LICHTANLAGENTECHN
  • EP2233820B1 patent drawingFigure 1~3
  • EP2233820B1 patent drawingFigure 4a~8
  • EP2233820B1 patent drawingFigure 9~11

AI summary

The invention relates to a lighting device with an extended, non-point-shaped light source, a reflector that conically surrounds the light source, and a lens for focusing the emitted light. The lighting device is characterized in that the lens (4) is arranged to be displaceable along an optical axis (5) of the lighting device (1) within a predetermined displacement range such that the focal point of the lens (4) can be displaced in the emission direction (7) at least in a region behind the hypothetical tip (9) of the reflector (3).