Article last updated on: Feb 10, 2019

Low-Temperature Polycrystalline Oxid, or LTPO, is an OLED display backplane technology developed by Apple. LTPO combines both LTPS TFTs and Oxide TFTs (IGZO, Indium Gallium Zinc Oxide). LTPO is applicable for both OLED and LCD displays, actually, but this backplane technology is likely to be used exclusively in high-end OLED displays

Apple LTPO OLED backplane (IHS slide)

In LTPO, the switching circuits are using LTPS while the driving TFTs will use IGZO materials. This could lead to a power saving of around 5-15% compared to the currently-used LTPS backplanes. The main drawback of LTPO, however, is that the IGZO TFTs are larger and so the display density may be compromised.

In September 2014 Apple introduced the world's first device to use an LTPO backplane - the Watch Series 4. Compared to the current-generation Watch, the new series has a larger AMOLED display - 1.78" 448x363 on the 44 mm watch and a 1.57" 394x324 one on the 40 mm model.

Apple Watch Series 4 photo



The latest LTPO OLED news:

China's first flexible semiconductor industry base project release, has the exclusive technology

The following is a sponsored post by Shaanxi Kuntech Semiconductor Technology

The press conference for the landing and launching of Shaanxi Kuntech Flexible Semiconductor Service Manufacturing Base Project was grandly held in West Fengxi New City, West Xian Xin New District, Shaanxi province on the morning of October 16, with its theme being "Shinning Shaanxi and Shaping the Future World".

Kuntech flexible AMOLED prototype photo

A number of Chinese government leaders, partners from home and abroad, as well as the media attended the event, where the duo direction foldable AMOLED display with internal and external folds developed by the R&D team was also displayed.

Several Apple Watch series 4 customers complain of a strong off-angle blue tint

Apple recently launched its latest smartwatch - the Watch Series 4. It seems that at least some customers are complaining about a strong blue off-angle blue tint on the new OLED display. Some of these customers say that the tint is stronger compared to previous generation Watch devices - and also stronger than the tint on the iPhone X and LG OLED TVs.

Apple Watch Series 4 photo

It's not clear whether this is a real issue or not at this stage - we only have heard of a few customers complaining so far. But this is interesting as Apple has adopted its new LTPO backplane technology in the Watch 4, which could be responsible for the stronger tint (Is this the beginning of LTPO-gate?). All previous Watch devices used flexible AMOLED displays made by LG Display. We do not know yet whether LGD is still the exclusive supplier, or whether Apple added Samsung Display as its second source (or even exclusive).

IHS: Apple is developing a new LTPO backplane, may introduce it in future iPhones

IHS posted an interesting article which details a new backplane technology that Apple is developing. So-called Low-Temperature Polycrystalline Oxide (LTPO) combines both LTPS TFTs and Oxide TFTs (IGZO, Indium Gallium Zinc Oxide). LTPO is applicable for both OLED and LCD displays.

Apple LTPO OLED backplane (IHS slide)

In LTPO, the switching circuits are using LTPS while the driving TFTs will use IGZO materials. This could lead to a power saving of around 5-15% compared to the currently-used LTPS backplanes. The main drawback of LTPO, however, is that the IGZO TFTs are larger and so the display density may be compromised. IHS says that Apple may introduce this into future iPhones - but it also says that LTPO will be limited to low-density displays at first which is a bit confusing.

Cambridge Isotope Laboratories - Deutreated Reagents and High-Purity Gases for OLEDsCambridge Isotope Laboratories - Deutreated Reagents and High-Purity Gases for OLEDs