Interior lighting: from functional to dynamic lighting – An interview with OSRAM OS

Interior lighting is gaining increasing importance as not only ambient lighting systems providing comfort, but also as supporting and functional systems linked with ADAS.

According to Yole Développement’s latest report Automotive Interior – From Lighting, Sensing to Display Technologies 2020, the interior lighting market is expected to grow from $3.1B in 2020 to $4.6B in 2025, representing an 8% compound annual growth rate (CAGR).

30 or 40 years ago, illumination was simple, and interior lighting was purely functional. Now, with the development of ADAS functionalities, lighting is not only used for ambient lighting but also for interaction between the car and the driver. Yole, the market research & strategy consulting company, had the opportunity to interview Osram OS, as the leading LED supplier for automotive lighting.

Martin Vallo, Market and Technology Analyst, Solid-state Lighting at Yole Développement (Yole), had the opportunity to talk about interior lighting and innovation with Stephan Hartmann, General Manager Automotive Interior and Michael Brandl, Head of Application Engineering Automotive Interior, both at Osram OS.

Discover the details of their discussion below.

Martin Vallo (MV): OSRAM OS is a global leader in LED lighting and sensing technologies and develops products for diversified interior and exterior automotive applications. Please describe your activities in automotive interior applications.

OSRAM OS: We are currently addressing three different application fields for automotive interior. The illumination part with white and dynamic RGB LED solutions for ambient lighting, as well as conventional products for functional lighting. The visualization part features different solutions for automotive interior displays, HUDs, and other projection applications. And the sensing part showcases infrared light-based applications like driver or in-cabin monitoring.

MV: Interior lighting is gaining increasing importance as not only ambient lighting systems providing comfort, but also as supporting and functional systems linked with ADAS. Could you give more insight into this context?

OSRAM OS: We see the car as a growing ecosystem, which is becoming more complex with every new vehicle generation. When you think of cars 30 or 40 years ago, illumination was simple: front lighting was bright, and the interior lighting was functional. But times have changed. With the development of ADAS the whole car, especially the interaction with the car, changes fundamentally. Different applications will need to work closely together in future.

One example, the LiDAR system in a semi-autonomous car registers a possible danger in oncoming traffic. The driver monitoring system detects that the driver is currently not paying attention because he’s talking to his child in the back seat. But thanks to dynamic lighting applications, which are integrated, for example, in the doors or the roof, the driver’s attention can be brought back to the road to avoid an accident.

MV: Why are the attributes of automotive LED, such as color accuracy, brightness, and resolution, so important?

OSRAM OS: As a component supplier for the automotive industry with more than 40 years of experience, we know how to serve the high-quality expectations of our customers. Regarding interior lighting, color accuracy plays a vital role. High-end interior lighting applications today are far more than just light on, light off. They are one of the central components of the interior design, the visual design language of the OEMs, so to speak.

As the human eye can already perceive slight color differences from nearby light sources, even the tiniest deviations in color are unacceptable. When you think of brightness and resolution – especially regarding exterior lighting – both aspects are of high importance for safety. A brilliant combination of both aspects is our Eviyos technology for ADB solutions. We’re currently working on the second generation with more than 25,000 individually addressable pixels. This product will enable very bright and precise front lighting, as well as high-resolution projections on the road. It will be launched in 2023. Resolution also plays a central role in displays with miniaturized light sources for automotive interiors.

As mentioned above, additional optical, thermal, electronical, and mechanical parameters are of great significance for high-quality applications. We have strong capabilities to simulate and support designs in these areas. In general, the design is eased by maintaining standard package families and consistent footprints, so existing design-know-how can easily be transferred to similar LEDs by our customers.

MV: In the summer of 2020 ams announced the successful closing of the OSRAM acquisition. How will the relationship with ams leverage your portfolio of lighting and sensing products and technologies? What are your plans for the future?

OSRAM OS: We are convinced that we can create an uncontested leader in photonics and sensing together with ams. We are currently looking closely at the portfolios of both companies to identify possible synergies regarding future product development activities. But of course, the combination of light with sensors opens a wide range of applications for automotive exterior, as well as interior. In the end, our customers will benefit from the deep application know-how from both sides.

MV: We observe significant transformation of the automotive interior market today. How has the interior lighting business changed in the past 5 years? What are the main drivers today?

OSRAM OS: Indeed, interior lighting has changed significantly over the last few years. From very functional lighting available in limited brand colors, to now where we are designing distributed and well-orchestrated lighting solutions. This can include both dynamic, as well as varying, color effects. The requirements for suppliers have become more complex, closely linked to the development of these more advanced interior lighting applications. General trends, like the miniaturization of components, is one central aspect here.

With ever smaller LEDs you can address completely new system designs and enable new applications, which wouldn’t have been possible before. In terms of visualization and the integration of extremely small light sources in different materials, there are many exciting new use cases to come. Dynamic lighting also plays an important role in the future. LED suppliers need expertise beyond light sources to create dynamic light. That’s why we work on various IC solutions to develop high-end products, like our intelligently addressable Osire RGB LED for automotive interior lighting.

In addition, we see tunable color temperatures becoming more important for automotive interiors. With our new Ostune product family, we presented the first automotive qualified LED with CRI >90. The broad color temperature range from 2700 to 6500 Kelvin enables OEMs to offer distinctive light variants for their ambient lighting: from elegant, bluish, cool white to cozy, reddish, warm white.

All these options allow car manufacturers to create highly customized and even adaptable user experiences. This can be realized both for night and daytime, ambient and functional lighting, as well as for welcome and good-bye scenarios.

MV: The biggest trend in automotive interior lighting is the seamless integration of lighting, sensing, and display technologies. It is evident this trend is impacting not only technological development but also the competitive industrial landscape. How do you see this trend evolving from both perspectives?

OSRAM OS: Thanks to our broad portfolio, including all three main lighting technologies (LEDs, Edge Emitting Lasers and VCSELs), we are able to address a wide variety of applications within the automotive area. Over the past few years, we have seen a clear increase in light-based applications in upcoming car generations. For us, it’s extremely important to have a well-balanced portfolio and a close relationship to customers to defend our leading position in the market.

MV: What are the technology difficulties in creating eye-catching dynamic lighting effects? What are the major approaches to meet the expectations of OEM lighting designers?

OSRAM OS: Color accuracy, miniaturization, seamless integration of components and the combination of lighting and sensing are key methods for meeting OEM expectations. With technological inherent distribution of wavelengths in LED production, solutions must be found to deliver a homogeneous light experience to the user. Very often, this demands an in-application calibration of the various LEDs. Our Osire product portfolio offers a broad range of solutions.

First, it uses pure RGB LEDs for external calibration and driver infrastructures.

Second, it includes an RGB LED with a data matrix code. This code allows access to the LED brightness and color data, which we log during our end-of-line testing anyway. While external drivers are still necessary, it eliminates the need for costly in-application calibration as the data can be directly fed into the control logic to calibrate differences using software algorithms. Our outstanding application engineering team can provide these respective algorithms.

Finally, we also offer a range of solutions with driver and LED data already included in the LED package. This eliminates both the need for external drivers and in-application calibration. The communication speed of these products is very fast, allowing dynamic effects to be used as warning functions. Additionally, the size of the infrastructure, for example. PCB layout space, can be reduced, allowing these applications to emerge without causing impossible to address space constraints.

Talking about space constraints, we complement our Osire portfolio with a high brightness, low profile RGB side looker for applications that are too thin for a top looking LED.  Therefore, we answer the various challenges with a wide variety of solutions to make finding the correct level of data and driver easy. All of these RGB solutions are complemented by the before mentioned Ostune white portfolio.

MV: Traditionally, all lighting systems have been supplied by Tier-1s which have specific lighting and electronics expertise. Nowadays, even the traditional players suppling interior parts, such as instrument panel, console and door trims, envision their product with integrated lighting, sensing or even display technologies. How do you see this trend developing? Will traditional interior lighting suppliers survive, or will they transfer their know-how to interior parts suppliers?

OSRAM OS: This process can be described as the spread or democratization of light. Today, innovations have the power to restructure the competition in the market fundamentally. Well-established players can now strengthen their market position by developing a strong IP portfolio.

We currently see two reasons why more and more companies are entering the lighting part of the game. With light functions spreading from a few functional spots to the whole interior design space, there is a need for traditional trim suppliers to figure out how to include light in their products. On the other hand, more advanced solutions on the LED side, including integrated drivers, have eased the application process of complex light functions, even for players that are not lighting experts. Our portfolio allows customers to choose just the right amount of electronics and data integration, based on what their experience and existing electronics design libraries allow.

MV: We are coming to the era when many different lighting/sensing technologies can coexist. It’s a new opportunity for OEMs to differentiate themselves from their competitors. How do you see the future of automotive interior in terms of lighting, sensing, and display applications? Will we see rather meaningful interior designs or a “Christmas tree”-like approach? Do you think that car models will look different in different regions?

OSRAM OS: We are convinced that the automotive interior market will grow significantly over the next years, creating more than enough space and potential for many new approaches and technologies. The final configuration of cars could differ from region to region, meaning that the same car platform in Europe could appear slightly different in China.

But new technological approaches already enable this flexibility without any significant changes in hardware. With the outside of cars being limited by aerodynamic-drag considerations and regulatory limitations in many countries, the interior gives more freedom to differentiate with light.

This is more and more true not only for light used at night, but also during the day. Our products, especially the Osire RGB family, are designed to be powerful enough for daytime use, as well as at nighttime, when they are dimmed to avoid glare. With virtually unlimited options, differentiation is indeed possible. It is up to the OEMs based on their branding and regional market whether a “Christmas-tree” or a more “meaningful” design is chosen.

MV: How is the COVID-19 pandemic affecting the automotive interior market?

The COVID-19 pandemic led to serious uncertainties for suppliers.  Automotive suppliers are confronting a challenging situation in the market as the outlook is still limited. But we are hopeful and see revitalization with the pandemic acting as a catalyst for the industry regarding developments in e-mobility and assisted driving.

Images – Courtesy of OSRAM OS, 2020


Stephan Hartmann, General Manager Automotive Interior at Osram OS

Stephan Hartmann is General Manager for Automotive Interior at OSRAM Opto Semiconductors. He joined OSRAM in 2017 as global Head of Automotive Marketing. Previously, he held several positions in application engineering, product marketing, and PL management. He studied Chemistry and the German language. Stephan has a PhD in Chemistry as well as an MBA in General Management and Global Business.

Michael Brandl, Head of Application Engineering Automotive Interior at Osram OS

Michael Brandl is Head of Application Engineering for Automotive Interior at OSRAM Opto Semiconductors. He studied Microsystems Engineering at Fachhochschule Regensburg, Germany before joining OSRAM in 2002. Since then, he has held several positions in applications engineering and customer quality management.


Martin Vallo, PhD, serves as a Technology & Market Analyst specializing in solid-state lighting technologies, within the Photonics, Sensing & Display division at Yole Développement (Yole). With 9 years’ experience of semiconductor technology, Martin is involved today in the development of technology & market reports as well as the production of custom consulting projects at Yole. Prior to his mission at Yole, he worked at CEA (Grenoble, France), with a mission focused on the epitaxial growth of InGaN/GaN core-shell nanowire LEDs by MOCVD and their characterization for highly flexible photonic devices. Martin graduated from Academy of Sciences, Institute of Electrical Engineering (Slovakia) with an engineering degree in III-nitride semiconductors.

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