Under-Display sensors

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.

Samsung and BOE has a long legal battle in the US, over OLED patents as Samsung Display claims BOE infringes upon its OLED patents. Earlier this year the US ITC decided that BOE infringes on several of SDC's AMOLED patents. Last month SDC filed another lawsuit, this time in the US District Court for the Eastern District of Texas, saying that BOE infringes upon four of its AMOLED TFT patents.

BOE has now filed its own patent infringement lawsuit against Samsung Display, also in the Eastern District of Texas Federal Court. BOE says that SDC's under-the-OLED camera solution used in its foldable Galaxy Z Fold series infringes upon four of its patents (specifically US11,037,994, US12,266,309, US12,307,976 and US11,695,017).

Researchers from Korea's Pohang University of Science and Technology (POSTECH) have developed the world's first pixel-based local OLED sound technology, which enables each pixel of an OLED display to simultaneously emit different sounds, essentially allowing the display to function as a multichannel speaker array. The researchers demonstrated the technology using a 13-inch OLED panel.

The researchers created the sound system by embedding ultra-thin piezoelectric exciters within the OLED display frame. These piezo exciters, arranged similarly to pixels, convert electrical signals into sound vibrations without occupying external space. As a result, each pixel can act as an independent sound source, enabling Pixel-Based Local Sound technology. The researchers also developed a method to completely eliminate sound crosstalk, ensuring that multiple sounds from different regions of the display do not interfere with each other.

Samsung Display is showing several new displays and technologies at Displayweek 2025. First up we have Samsung's latest Sensor OLED display protype that allows for allows fingerprint recognition and cardiovascular health monitoring across the entire screen surface. 

To create this display, SDC integrated OPD directly during the OLED deposition process, embedding the sensors into the panel itself (what is sometimes referred to as a bi-directional OLED). Beyond fingerprints, it measures biometric data such as heart rate, blood pressure and stress levels. This technology is based on how OLED light reflects differently depending on the contraction and relaxation of blood vessels.

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.

Researchers from Koreas Pohang University of Science and Technology (POSTECH) with support from LG Display, developed the world's first smartphone-type OLED panel that can freely transform its shape while simultaneously functioning as a speaker. LG Display have developed and commercialized OLED that act as speakers for both smartphones and TVs many years ago - but this is the first time that such a technology is applied to a truly flexible display.

The POSTECH research team used a specialized ultra-thin piezoelectric polymer actuator to create the OLED speaker, and when integrated into a flexible OLED panel, this actuator enables electrically driven shape transformation into a wide variety of complex forms—not only concave curves, but also convex, S-shaped, inversed S-Shaped and wave-like configurations that respond dynamically, almost like a display in motion.

BOE technology announced that it developed a new under-the-display OLED camera solution, to enable full-screen smartphone OLED displays with higher quality cameras than before. The company held a ceremony together with ZTE's Nubia and Red Magic smartphone brands, saying that it will supply the display and camera solutions to flagship smartphones from these two brands soon, the Nubia Z70 Ultra and the Red Magic 10 Pro.

BOE says that the new AMOLED displays adopt several innovative technologies, such as SIP ultra-narrow bezels, COP packaging - and the new under-the-OLED camera. The new technology achieves a full 430 PPI resolution for the OLED display including in the camera area, and the smartphones will offer a 95.3% screen-to-body ratio (as there's no notch or punch-hole). 

During Displayweek 2024, Visionox demonstrated many OLED display technologies and panels, and also an interesting microLED prototypes (produced by its subsidiarity Vistar).

Visionox is in the final stages of development of its ViP maskless display production process, and the company showcased some nice ViP smartphone panel prototypes (the technology can be used for any panel size). ViP offers a high improvement in aperture ratio (69% up from 29%) which results in low power consumption and brightness (up to 4X according to Visionox), improved lifetime (up to 6X), improved PPI and more.