Micro-Lens Array (MLA)

Researchers from KAIST, led by Professor Yoo Seunghyup, developed a novel quasi-planar light extraction structure that enables to more than double the light output from OLED devices.

The researchers optimized the radiative power transfer in finite-sized OLED emission and reception areas, and then added a quasi-planar light extraction structure that has both a curved section and a straight section. Experiments have shown that this design minimized light loss caused by back-reflection within the structure and allowed more light to be emitted externally within a limited space.

Tianma Microelectronics has established itself as one of the world's leading AMOLED producers, building on its legacy as an LCD producer. The company produced almost 60 million OLED displays in 2024, and it has grown over 20% in 2025, and produced over 75 million panels.

Tianma is not amongst the world three leading OLED producers (Samsung, BOE and LG Display), but it is a strong competitor, and holds an estimated 8-10% of the total smartphone AMOLED market. The company is also building strong capabilities in automotive OLEDs, and high-end smartphone AMOLED displays. In this article, we detail Tianma's history, AMOLED capabilities and fabs, its technology roadmap, opportunities and challenges, and its microLED and ePaper projects.

China-based Tianma is showing many OLED displays and prototypes at SID Displayweek 2025. First up are two 13" concave displays (C-shaped and L-shaped), aimed for automotive dashboards. The company says that these distinctive contours not only deliver a striking visual experience but also helps enhance driver focus. Both displays are based on Tianma's tandem OLED architecture, which the company calls SLOD (Stacked Layer OLED Device, more on this below).

The second display is a 6.67" AMOLED that integrates a microLens array (MLA, which Tianma refers to as MLP or Micro Lens Pattern). Tianma says they adopt an innovative optical design to significantly boost the front-view light extraction efficiency. Tianma also shows a 6.78" tandem (SLOD) smartphone AMOLED display, to increase power efficiency. Tianma says that unlike traditional tandem OLEDs, its SLOD technology adopts a CGL structure with an extremely low device voltage using a differentiated light-emitting unit - thus achieving higher power efficiency. Tianma reports that the power consumption is reduced by 30% compared to a single-layer device, while brightness is increased by 25% and lifetime is up to four times higher.

Sony announced a new OLED Microdisplay, the ECX350F, a 0.44" 120Hz 1920x1080 (FHD) microdisplay that offers the world's highest brightness at 10,000 nits. It also offers the world's smallest pixel size at 5.1 um (the PPI is around 5,000).

Sony says that in order to reach this high brightness, it adopted a new OLED stack structure, a new "semiconductor process" and added a microlens array on top of the display. In addition, the bezel size of the new display is exceptionally small, with only 1.14 mm of added bezel on the long side of the display on both top and bottom.

According to reports from Korea, Microsoft has signed an agreement with Samsung Display for the supply of OLED microdisplays for a future MX device, that Microsoft plans to launch in the future (likely 2026 or later).

Microsoft agreed to order a few hundreds of thousands of units of Samsung's OLED microdisplays. Samsung Display is collaborating with Samsung System LSI, that will design the CMOS backplane, which will be produced by Samsung Foundry. Samsung Display will handle the frontplane OLED deposition and encapsulation.

OLED displays have been gaining popularity rapidly, and are already the dominant smartphone display technology. OLEDs are also the display technology of choice in the smartwatch market, making inroads into the TV, monitor, laptop and tablet markets. The future of the OLED industry looks bright.

In recent years, the focus of the industry, beyond increasing capacity and reducing production costs, has been improving the performance of OLEDs in the areas of display brightness, efficiency, and lifetime. Brightness is required in many applications - from TVs (for HDR and to view in ambient lighting) through smartphones (outdoor viewing) to automotive, and efficiency is a plus in any scenario (but mostly in mobile displays). Display lifetime is already good enough for many applications, but in some cases (like automotive, and IT displays) it is critical. These three properties usually go together - if you can make more efficient OLED displays, you can drive them at a lower current to achieve the same brightness, and so lifetime increases, or you can achieve higher brightness, etc. 

Since Samsung started mass producing AMOLED displays in 2007, most people believe that the company is not only the leader in OLED production capacity, but also in the performance of its displays. In most cases, Samsung has been the first company to develop and manage to mass produce the most advanced OLED displays, and the first to adopt the latest OLED materials, architectures, and processes.

There are some signs that this could be changing, although honestly it's a bit too early to know. In May 2024, Apple launched its first OLED Tablets, and according to reports, Apple chose LG Display as its main supplier, ordering around 60% of its iPad OLEDs from LGD (with all of the 13" model orders going to LG), and the rest from Samsung. Later it was reported that Apple had to delay the introduction of its 2024 iPad Pro devices as Samsung faced low production yields and could not deliver displays in time.

LG Display demonstrated its latest OLED display prototypes and commercial panels at Displayweek 2024. The company showed flexible panels, automotive displays, transparent OLED, gaming monitors, a 10k nit microdisplay and more.

So first up, LG Display shows its automotive Advanced-Thin-OLED (ATO) displays, which are produced on glass substrates and use a tandem structure. These OLEDs are lower in cost compared to LGD's flexible automotive p-OLED panels, but still enable low-weight and thin profile, and the excellent image quality of an OLED display. The smaller display was a 12.3" 2400x900 (209 PPI) 1,000 nits panel, while the other panel was larger at 17" 1920x2560 (188 PPI).

LG Display developed a new OLED microdisplay (OLEDoS) that achieves a brightness of 10,000 nits. This development is presented at SID DisplayWeek 2024. 

To achieve this high brightness, LG Display's research team used newly-developed high performance OLED materials, and also used a micro lens array (MLA) to expand the light output from the device. 

LG Display announced that it has developed its 2nd generation Multi-Lens Array (MLA) technology, branded as META Technology 2.0.  The company demonstrated a 83" META 2.0 OLED TV panel, during CES 2023. The company will apply this technology to several of its 2024 OLED TVs, ranging in size from 55-inch to 88". 

META 2.0 WOLED panels achieve a peak brightness of 3,000 nits - a 42% improvement over the company's conventional panels. LGD explains that META 2.0 includes a pattern of optimized micrometer-scale lenses with an optimized lens angle, an upgraded "brightness enhancing algorithm" called META Multi Booster, and a full-range brightness detail enhancing algorithm called Detail Enhancer. All of these new technologies, combined, makes for a META 2.0 panel. In a 77-inch 4K panel, there are 42.4 billion micro lenses (!).