Opixs, the New Display Simulation Software from Fluxim
Opixs is Fluxim’s latest simulation software, developed to address the increasing complexity of today’s display technologies. With Opixs, researchers and engineers can design and check new pixel architectures to find layouts that use less power and deliver better colour, before building them.
Opixs is intended for use in both academic and industrial settings, helping users:
Test new subpixel concepts
Optimize display power budgets
Understand the impact of layout changes on efficiency
Support sustainability goals by reducing unnecessary power use
Whether you are developing energy-efficient mobile displays or high-performance large panels, Opixs can support your work.
Figure 1. Opixs simulation workflow from the JV characteristics of the single pixels to the properties of the display.
Built for Display Innovators
Opixs simulates display power and colour characteristics at the subpixel, pixel, and screen level. It supports customized subpixel concepts such as:
Standard RGB
RGBW (Red, Green, Blue, White)
OLED pixel configurations (RGBW, White + CF, Tandem RGB, QD-LED)
TurboLED and advanced custom layouts
The subpixels can be arranged both laterally and horizontally.
Each pixel layout presents unique trade-offs between luminance, colour gamut, and power. Opixs enables users to make these trade-offs visible and measurable.
Core Capabilities
At the heart of Opixs is a comprehensive physical model that calculates:
Most efficient subpixel combination
Power per subpixel and per subpixel combination
Total display power and power density
Power per emissive area
These calculations are based on user-defined parameters such as subpixel JVL characteristics, dimensions, and colour coordinates, and depend on target display content and luminance. The tool also accounts for relative subpixel areas and allows users to compare configurations under consistent conditions.
Fig. 2 Example pixel layouts supported by Opixs, RGB, Tandem RGB, RGBW, White +CF , QD-OLED and TurboLED®
For the given layout, Opixs computes how light and power are distributed across individual subpixel types and aggregates these into meaningful performance metrics for the full display. For layouts with > 3 subpixel types, Opixs automatically computes the most economic colour representation and makes the potential power savings quantifiable.
This level of detail is particularly valuable for next-generation display types such as microLED or OLED-on-glass, where maximising emissive efficiency is essential for both performance and thermal management.
Opixs Selected for I-Zone 2025
We’re proud that Opixs, Fluxim’s new display simulation software, was selected as a contender for the 2025 I-Zone awards at Display Week—highlighting its potential to advance display technology R&D.
In this video from Display Week 2025, Prof. Beat Ruhstaller explains how Opixs simulates and optimizes pixel and sub-pixel layouts for more power-efficient, high-performance displays. He also shows how it complements Fluxim’s established tools like Setfos (for stack simulation) and Laoss (for large-area optics). Tech journalist Charbax captured the demo live at the event.
📄 Full Interview Transcript
Below is the full transcript of Prof. Beat Ruhstaller's I-Zone presentation at Display Week 2025, recorded by tech journalist Charbax.
(Click the + to expand and read the full text.)
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Hello, this is Beat Ruhstaller. I'm the founder of Fluxim, and it's exciting to be here again at SID. This time, we are introducing a new tool called Opixs. It's a software tool that we are launching this year, and it complements our other tool, Setfos, which is well known in the industry.
This new tool allows users to define sub-pixel layouts. Any display is composed of red, green, and blue sub-pixels. The challenge is to choose the exact color and JVL characteristics—such as color coordinates—for each sub-pixel. For example, on the left, you see a traditional RGB layout where red, green, and blue sub-pixels are placed side-by-side. But you can also have tandem displays, where two red, two green, and two blue sub-pixels are stacked, or even different variants of each—something we refer to as a "turbo" concept.
Once you choose a sub-pixel configuration, you can load any image into the software. It calculates the power consumption of every pixel in the target image, based on the selected sub-pixel layout and the desired display brightness. Then you can modify the configuration and compare power consumption results between, for example, a traditional layout and a stacked concept. Traditional configurations often use more power, while stacked layouts can avoid efficiency roll-off at high brightness levels. This is because stacked sub-pixels provide a larger emitting area, allowing better performance at lower current densities.
Fluxim is known for these kinds of innovations. Our simulation tool Setfos has been used in the OLED industry for over 20 years. It's a well-established software for electrical and optical modeling. We also offer hardware like Phelos, which is an angular measurement instrument for characterizing OLED emission and photoluminescence versus angle—essential for OLED quality control. Another instrument, Paios, is used for AC, DC, and transient characterization of OLED pixel dynamics such as turn-on and turn-off behavior.
Opixs fits into this ecosystem nicely. For example, you might start by using Setfos to design the OLED stack at the layer level. From that, you can extract current-voltage-luminance data and color coordinates, and input them into Opixs. Opixs then performs higher-level calculations at the display level—estimating full display power consumption. This helps predict the potential battery savings in mobile devices, which is a key driver for OLED display optimization.
Our customers are often R&D teams in OLED fabrication companies. They experiment with new layer stacks and materials, often provided by suppliers. Using our tools, they can simulate expected performance before fabricating prototypes—saving time and cost. Setfos is ideal for sub-pixel simulation, while Opixs now enables comparison across full-display configurations, such as various sub-pixel arrangements.
Tandem OLEDs are a key innovation. Apple has already introduced this concept in their products. Though they are more complex to fabricate—since you double the number of layers—the benefit is that you can run the OLEDs at lower current density while achieving the same brightness. This reduces degradation and significantly extends device lifetime. Tandem OLEDs can also reach higher peak brightness levels. For example, RGB sub-pixels stacked vertically to form white OLEDs are used in Apple’s Vision Pro display. Stacked OLEDs have gained popularity in recent years.
Opixs is fully compatible with this evolution. It allows users to explore new display concepts—not just in terms of power savings, but also regarding color performance. One ongoing challenge in the display industry is balancing color gamut with power efficiency. Deeper, more vibrant colors often consume more energy. Opixs lets you play with different sub-pixel combinations—mixing deep and light tones—to create displays with more than three sub-pixels, potentially up to six per target pixel.
Since we last appeared together in a video about five or six years ago, Fluxim has grown steadily. We're now a team of around 40 staff members. We currently offer four measurement instruments and two established simulation software tools. Opixs will soon become the third simulation tool in our portfolio. Beyond the display industry, we also serve the solar cell field and are starting to branch into battery research—another area where our R&D tools help scientists and engineers innovate more effectively.
We have a strong R&D team that actively participates in collaborative projects—mainly across Europe but also with partners in Korea and other countries. These projects keep us connected to the latest research needs and help us tailor our products accordingly. Our team often travels to partner labs—for example, in the UK—to carry out measurements directly on OLED or solar cell samples. Both Fluxim and our customers publish frequently; over 100 research papers reference our R&D tools, which gives us valuable visibility.
Fluxim remains proudly based in Switzerland—in Winterthur near Zurich. Internationally, we work with distribution partners in China, South Korea, and Japan. These local partners provide first-level support, and our internal team is always ready to assist with more complex inquiries. While some of us speak Swiss German, English is our working language—especially with our many European colleagues. So we’ve become quite an international team.
