Flexible LED Strip with Translucent Housing for Homogeneous Light

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Solution Overview

Problem

Existing flexible LED strips are limited in their ability to bend around a vertical axis and achieve homogeneous light emission over 180°, with inadequate heat dissipation and modularity for advanced lighting applications.

Innovation Solution

A flexible LED strip design featuring a U-shaped housing with translucent second casting compound on one leg, embedded in transparent first compound, and reflectors on the legs to diffuse light and enhance heat dissipation, allowing for modular assembly and efficient light distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a U-shaped housing with two-layer casting compound is used, then homogeneous light emission is achieved, but the device becomes less flexible in bending around vertical axis

Engineering Contradiction:
Improvehomogeneous light emissionVSAvoidflexibility to bend around vertical axis
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The housing is divided into two functional segments: a rigid U-shaped housing providing structural support and optical homogenization, and a flexible conductor carrier with LEDs that can be bent. This segmentation allows the rigid part to ensure homogeneous light emission while the flexible part maintains bendability around vertical axes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the device have different mechanical properties: the U-shaped housing with two-layer casting compound provides rigidity and optical homogeneity, while the conductor carrier with mounted LEDs provides flexibility. This local differentiation of material properties resolves the contradiction between homogeneous light emission and vertical bending capability.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If transparent potting compound is used to embed LEDs, then light transmission is improved, but heat dissipation becomes inadequate

Engineering Contradiction:
Improvelight transmissionVSAvoidheat dissipation
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent employs a composite material strategy by using transparent potting compound for light transmission while incorporating thermal management features such as heat sinks or thermally conductive structures within the housing. The two-layer casting compound system combines optical transparency with thermal management capabilities, allowing simultaneous achievement of light transmission and heat dissipation.

Inventive Principle:
Principle #40Composite materials

3Illumination intensity

If the housing is made opaque to scatter light, then homogeneous light output is achieved, but light transmission efficiency decreases

Engineering Contradiction:
Improvehomogeneous light outputVSAvoidlight transmission efficiency
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The housing employs local quality differentiation with a transparent first casting compound layer that allows efficient light transmission, and an opaque or translucent second casting compound layer that provides light scattering for homogeneity. This layered approach with different optical properties at different locations achieves both light transmission efficiency and homogeneous light output.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The two-layer casting compound system creates a composite optical structure where the transparent lower layer transmits light efficiently from the LEDs, and the opaque/translucent upper layer scatters the light to achieve homogeneous emission. This composite material approach resolves the contradiction between light transmission efficiency and homogeneous light output.

Inventive Principle:
Principle #40Composite materials

4Loss of time

If rapid filling of casting compound is performed to reduce shrinkage, then manufacturing time is reduced, but air pockets and defects increase

Engineering Contradiction:
Improvemanufacturing timeVSAvoidabsence of air pockets
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

The patent employs preliminary action by designing the mold with specific features such as overflow edges and vacuum channels that prepare the casting process in advance. The mold geometry is pre-configured to facilitate air evacuation and compensate for shrinkage, allowing rapid filling without creating air pockets or defects.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces intermediary elements in the casting system, such as vacuum channels or overflow edges, that mediate between the rapid filling process and the quality requirements. These intermediary features enable fast filling while preventing air pocket formation by providing escape paths for air and compensating for shrinkage.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design enables flexible LED strips that can bend vertically, achieve homogeneous light emission over 180°, and provide effective heat dissipation, leading to longer service life and energy efficiency in lighting applications.

Implementation Method 1

the second casting compound, in particular an opaque second casting compound, in which light from the light-emitting diodes is heavily scattered

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

the light emitted by the light-emitting diodes can initially pass unhindered through the transparent area of the first casting compound to the underside of the second casting compound

Methodology Applied
Scientific EffectLight transmission: Refraction

Implementation Method 3

with two sealing compounds arranged between the two legs of the housing... at least the first leg of the U-shaped housing consists of a translucent second casting compound that tapers in wall thickness and merges into the plastic material of the housing

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3361150B1Horizontally or vertically flexible light emitting diode strips with homogeneous light output and method for their production
Publication Date: 2019.06.19 JOSEF BARTHELME
  • EP3361150B1 patent drawingFigure 1~2
  • EP3361150B1 patent drawingFigure 3~4
  • EP3361150B1 patent drawingFigure 5~6

AI summary

1. Horizontally or vertically flexible LED strips with homogeneous light emission and methods for their manufacture. 2.1 LED strips, for example an LED luminaire, comprising a housing, i.e., a U-shaped mold, which surrounds several chip LEDs spaced apart from one another on a ribbon-shaped, in particular flexible, conductor carrier, and filling the open U-shaped mold with first and second potting compounds, have long been known. 2.2 In order to enable a modular construction of the LED strips, at least the first leg (S1) of the U-shaped housing (U) consists of a translucent second potting compound (V2) that tapers in wall thickness and merges into the plastic material of the housing (U).that the flexible conductor carrier (T) is arranged on this leg (S1) and embedded in the first transparent potting compound (V1), and that the light from the chip light-emitting diodes (LEDs) is reflected from the inner surfaces of the housing (U) and diffusely emitted through the second potting compound (V2), the LED strip being elastically flexible in its extension direction. In the method for manufacturing the LED strip: a) a second liquid translucent potting compound (V2) is poured into a potting mold (F) open on one side, the contour of which is designed as legs (FS1, FS2) extending perpendicularly from this side and a filling rim (FR) rising towards the open end face, such that it forms a curved surface between the filling rim (FR) and an overflow edge (ÜK) of the potting mold (F),b) the plastic material of the housing (U) is filled up to the overflow edge (ÜK) of the potting mold (F), thereby forming the first leg (S1) and the base (UB) of the U-shaped housing (U), c) the flexible conductor carrier (T) with the mounted chip light-emitting diodes (LEDs) is inserted into the U-shaped housing (U) below a groove (SIN) of the first leg (S1) adjacent to the end of the second potting compound (V2), d) the first potting compound (V1) is filled up to the inner edge of the base (UB) and the opposite edge of the second potting compound (V2), and e) the second leg (S2) of the U-shaped housing (U) is filled up to the outer edge of the base (UB) and the opposite edge of the second potting compound (V2). 2.3 The invention lies in the field of light-emitting diode strips.