DE102022000971A1 - New light guide that specifically couples out the light from individual LEDs in multiple light pixels arranged over a large area - Google Patents

Abstract

Homogeneously illuminated surfaces have become standard design in display and lighting technology. Either panels that are illuminated by flatly arranged LEDs or flat light guides with lateral light coupling through LED strips are used. In order to save on LEDs and the necessary peripheral electronic components and circuit boards, adequately constructed light guides distribute the light from individual light sources to many coupling points through the light distribution imposed by the output geometry into the surface or strip. They replace flat or elongated circuit boards with a large number of individual LEDs applied

Description

Due to their high efficiency, lifespan and robustness, LEDs are now used for practically all lighting and display purposes.

Line lights and panel lights are often realized as long, narrow or large circuit boards with a large number of attached LEDs. The electronic circuitry and heat dissipation are integrated in and on the circuit board. Thanks to miniaturization and highly automated assembly processes, such technically complex lighting solutions have become economically feasible.

Like practically all semiconductor products, LEDs were also subject to further miniaturization. As expected, the amount of light per component decreases, but due to thermal effects and other economies of scale, efficiency and lifespan are also reduced.

With a growing social demand for the sustainability of products, recyclability after the usage cycle and the carbon footprint during production, lights and lighting application concepts with LEDs are now also subject to a social reassessment.

• - minimalen Einsatz chemischer umweltproblematischer Substanzen bei der LED
• - deren besserer Energieeffizienz
• - minimalen Einsatz umweltproblematischer Substanzen bei der Treiberelektronik
• - Vereinfachung der Treiberelektronik durch weniger Bauteile, weniger Leiterbahnen

In relation to the amount of light that can be generated per LED in relation to the size, there are more lumens per gram, and the efficiency lumens per watt also increases for larger designs. In the interests of sustainability, these contexts recommend the use of as few and powerful LEDs as possible. Similarly, with this reduction, significantly fewer materials with environmentally relevant components are used in the electronic circuitry and thermal management. It is therefore expedient to optimize the lighting solution using fewer - but more powerful - LEDs. in relation to

• - minimal use of chemical, environmentally problematic substances in the LED
• - their better energy efficiency
• - Minimal use of environmentally problematic substances in the driver electronics
• - Simplifying the driver electronics through fewer components and fewer conductor tracks

This reassessment will consequently, also due to a better cost structure, lead to the use of fewer LEDs whose system, operating and ecological parameters are optimized. The original light distribution of the individual light pixels (many micro LEDs) must then be implemented into the surface or line or other dedicated applications through the use of adapted light guides.

• - hocheffizient das Licht von LeistungsLED in den Lichtleiter einzukoppeln (3)
• - durch geometrische dreidimensionale Formgebung das Licht zum Anwendungsorten / den Anwendungsorten/ zu leiten (4)
• - das Licht und dessen Verteilung möglichst präzise gemäß der Anwendung auszukoppeln (5, 5a)
• - Typisch eine Vielzahl von präzisen Leuchtpixeln zu erzeugen, die bisher durch micro LED Bauelemente dargestellt wurden. (7)

The new light guides have the task of:

• - highly efficient coupling of the light from power LEDs into the light guide ( 3 )
• - to guide the light to the application location(s) through geometric three-dimensional shaping ( 4 )
• - to decouple the light and its distribution as precisely as possible according to the application ( 5 , 5a)
• - Typically to generate a large number of precise light pixels, which were previously represented by micro LED components. ( 7 )

State of the art:

1. A) Flächenlichtleiter, in die das Licht in der Regel über Kanteneinkopplung mit LED bestückten Platinen eingebracht wird. Die Auskopplung geschieht über
   • - räumliche Strukturierung einer oder mehrerer Oberflächen des Lichtleiters
   • - mechanisch oder per Laser aufgeraute Oberfläche(n)
   • - diffus transparentes Material des Lichtleiters
   • - im Material eingebetteten lichtstreuenden Partikel.
   • - Mit optischen Elementen mikrostrukturierte Oberfläche
   Flächenlichtleiter sind in der Anwendung als Displaybeleuchtung oder Leuchten verbreitet. (1) Ebenfalls bekannt sind Flächenleuchten, bei denen viele LED auf einer Platine in der Fläche verteilt offen oder hinter einer diffusen oder transparenten Abdeckung angeordnet sind. (2)
2. B) lineare, oft gebogene Lichtleiter mit rundem, ovalen, rechteckigem Querschnitt, in die das Licht einer Lichtquelle stirnseitig einkoppelt wird. Die Auskopplung geschieht über
   • - räumliche Strukturierung einer oder mehrerer Oberflächen des Lichtleiters
   • - mechanisch oder per Laser aufgeraute Oberfläche(n)
   • - diffus transparentes Material des Lichtleiters
   • - im Material eingebetteten lichtstreuenden Partikel.

Light guides are known as:

1. A) Surface light guides, into which the light is usually introduced via edge coupling with LED-equipped circuit boards. The decoupling happens via
   • - spatial structuring of one or more surfaces of the light guide
   • - surface(s) roughened mechanically or by laser
   • - diffusely transparent material of the light guide
   • - light-scattering particles embedded in the material.
   • - Microstructured surface with optical elements
   Surface light guides are widely used as display lighting or lights. ( 1 ) Also known are panel lights in which many LEDs are arranged openly on a circuit board over the surface or behind a diffuse or transparent cover. ( 2 )
2. B) linear, often curved light guides with round, oval, rectangular cross-sections, into which the light from a light source is coupled at the front. The decoupling happens via
   • - spatial structuring of one or more surfaces of the light guide
   • - surface(s) roughened mechanically or by laser
   • - diffusely transparent material of the light guide
   • - light-scattering particles embedded in the material.

Linear light guides are used for (colored) light displays, boundary markings and lighting applications, often in automotive technology.

Drawings:

• 1 Surface light guide as a luminaire
• 2 LED array as a light
• 3 Linear light guide with coupling collimator
• 4 Three-dimensional light guides with discrete light output interfaces
• 5 Coupling optics and light distribution
• 5a Coupling optics variants with adjustable light distribution
• 6a Linear light guides feed surface light guides via discrete coupling interfaces
• 6b circular light guide feeds circular light guide from the inside via discrete coupling interfaces
• 6c circular light guide feeds circular light guide from outside via discrete coupling interfaces
• 7 Multiple - linear finger light guide with regular light extraction across the area
• 7a Multiple - linear finger light guide with regular light extraction over the surface and double feed
• 8th Surface light guide with integrated linear light guide and coupling interfaces
• 8a Circular surface light guide with integrated linear light guide and coupling interfaces

Claims (9)

Light guide, consisting of transparent plastics or silicones, which couple in the light of an LED at the front and, through three-dimensional shaping, couple out the light for lighting purposes in other places with controlled light distribution. light guide Claim 1 , whose coupling geometry is optimized in terms of maximum coupling efficiency. light guide Claim 1 , whose coupling geometry specifically generates light angle distributions in the light guide light guide Claim 1 - 3 , which contain multiple decoupling elements ( 3 ) light guide Claims 1 - 4 , whose decoupling elements create special light distributions ( 8th ) light guide Claim 1 - 4 , which in turn guide the light into secondary light guides at their coupling points. ( 6a , 6b , 6c ) Light guides according to 1-5, which are split into multiple singular light guides with the claims according to 1-5 ( 7 , 7a) Linear light guides whose output geometry creates targeted angular distributions of light. 8a : coupling on both sides, 8b: coupling on both sides with coupling at angles Linear light guides that are integrally coupled to surface light guides (b: circular light guide)

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