In November 2019 ETNews reported that LG Display will supply Apple with 6.1" film-touch OLED flexible displays for its 2020 iPhones. Samsung will also supply the same displays (in a 50:50 split) in addition to 5.4" and 6.7" OLEDs that will support Samsung's on-cell touch (Y-OCTA).
According to a new report by ETNews, LG Display is set to update its E6 flexible OLED production line to support two new technologies - LTPO and on-cell touch, which LG calls TOC. ETNews says that LG's E6 line is dedicated to Apple - currently it produces 6.5" 2688x1242 OLEDs used in the iPhone 11 Pro Max.
LG obviously aims to supply more displays to Apple - and so it needs to implement the latest technologies. An on-cell structure enables thinner panels as the touch sensor is deposited directly on the encapsulation (TFE) layer. The optical features are also better as the touch layer is below the polarizer and enables the use of a non-ITO grid, there's no need for a support film (see image above) and the number of layers is lower.
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
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 Watch Series 3, 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. LG's current LTPO OLED displays are produced at LG's E2 fab in Paju, and in the future it will move the production to the E6 line. It is also possible that Apple is aiming to adopt LTPO in larger iPhones displays in the future.