OLED Polarizer

Omdia says that Color-Filter on Encapsulation (COE) will grow to be the dominant technology in foldable OLED smartphone panels, and will replace the currently-used circular polarizers. COE adoption will grow at a 33% CAGR between 2024-2030, and by 2030 almost 90% of foldable smartphones will use COE technology, and almost 20% of all smartphone OLED panels.

The adoption of COE in OLEDs increases the panel effective brightness, which means that the display consumes less power compared to a polarizer OLED (same brightness) and also lasts longer. The color gamut is also improved. On the other hand, COE OLEDs suffer from higher reflectivity compared to polarizer OLEDs. 

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.

In 2020, LG Chem announced that it has sold most of its LCD polarizer business to China’s Ningbo Shanshan, in a $1.1 billion deal. LG Chem retained its automotive LCD polarizer and its OLED polarizer businesses. The company now announced that it sold all of its remaining display polarizer business to two companies, for around $800 million deal - the polarizer materials business to Hefei Xinmei Materials Technology ($616 million) and the polarizer production business to Shanjin Optoelectronics ($200 million).

LG Chem aims to focus on its main growth engines, namely battery materials, green materials and life sciences. The company did not detail its plans for its remaining OLED businesses.

TCL (CSoT) announced that the company has finalized the development of several new OLED technologies, which has been deployed at the company's production lines.

The first technology is LTPO, or Low-Temperature Polycrystalline Oxide, an OLED backplane technology developed originally by Apple. LTPO enables variable refresh rates, and TCL's technology can support a wide range of frequencies, from 1Hz to 144Hz.

Samsung Display announced its latest OLED panel, the Eco²OLED, which increase light output by 33% compared to SDC's previous OLED panels. The increase light translates into a power consumption reduction of up to 25%.

For the Eco²OLED panel, Samsung finally managed to commercialize a polarizer-free OLED, after many years of R&D. The first phone to adopt this display will be Samsung's upcoming Galaxy Fold 3. Interestingly Samsung says that the new design also enabled it to incorporate a high-quality under-the-display camera as more light is entered through the OLED.

BOE demonstrates several new OLED technologies at SID Displayweek 2021. First up is a new rollable display. The new display is 8-inch in size, and it features a resolution of 2592x2176 and a bending radius of 4 mm. BOE says the new display passed over 200,000 sliding cycles.

Last year at Displayweek 2020, BOE demonstrated a 12-inch rollable OLED. It has since been working with LG Electronics on the company's rollable smartphone (which was since canceled as LG withdrew from the smartphone market) and with OPPO on a 7.4-inch sliding OLED phone.

In March 2021 Tianma unveiled a new OLED display technology, which it refers to as CFOT OLED - a polarizer-free OLED that adopts color-filters instead to remove reflections. The company demonstrated a 8.03" CFOT OLED prototype at SID Displayweek 2021:

Tianma says that a CFOT OLED enables a thinner design, improves the light emittance and also cuts the power consumption by 20%. The 8.03" display offers a resolution of 2000x2544 (403 PPI).

Samsung Display has been developing polarizer-free AMOLED displays for many years, and last year UBI detailed how the company plans to use color filters to eliminate the need for polarizers and so increase the efficiency of their OLED panels while also lowering the thickness.

DSCC posted an interested article that details Samsung's upcoming polarizer-free OLEDs, which it brands as POL-LESS OLEDs. The first OLEDs to adopt this new structure are expected to be adopted in Samsung's Galaxy Fold 3 later this year.

Researchers from the Imperial College London have devised a method to create strong chiral light emitting polymers OLEDs. These OLED devices emit efficient polarized light - which means that they could be used to create OLEDs without an anti-reflection polarizer filter and thus enable higher efficiency displays.

The researchers discovered that using thin films of aligned polymer LED devices shaped like fusili pasta it is possible to emit high chirality light.

UBI Research reports that OLED makers are aiming to adopt color filters instead of polarizers in foldable OLED displays. The polarizer help prevent internal reflections by external light, but they lower the brightness and limit the flexibility of the panel.

Using color filters instead of the polarizer may enable brighter panels and also thinner ones which are more flexible. BOE has already demonstrated such a panel back in 2017 (scheme shown above) - and they said it is 23% brighter than a polarizer OLED, and it is also 110 um thinner. Samsung Display is also developing similar technology.