Last week Patently Apple posted a report titled "Ming-Chi Kuo: Apple's Crease-Free Foldable iPad/MacBook Devices aimed for Q4-25 & H1-26 with LG the Exclusive Display Partner." One of the key points to Kuo's research regarding this project is that LG Display will be Apple's exclusive display supplier out of the gate.

Knowing that LG Display will play a major role in Apple's foldable devices, It's important to keep track of some of the developments occurring behind the scenes regarding LG Displays work on foldable displays.

In that vein, it was discovered today by The Elec that LG Display purchased black Pixel Define Layer (PDL) samples from Mitsubishi of Japan and others in the second quarter and is currently testing them.

Black PDL is a key material for Color Filter on Encapsulation ('COE') technology used to make foldable panels thinner.

The term CoE refers to the low-temperature printing of color filters (CF) on top of thin film encapsulation (TFE)that protects OLED from moisture and oxygen. Black PDL is the core of CoE.

In CoE, color filters and black PDL prevent light from reflecting from the outside and inside of the panel, respectively. In order to apply CoE to improve display visibility and reduce power consumption, black PDL technology must be secured.

LG Display's testing of black PDL appears to be in preparation for foldable panels. Currently, LG Display is working on CoE-related projects with several partners other than Mitsubishi. It has not yet been decided whether LG Display’s potential customers will apply CoE to foldable products.

Samsung Display is mass-producing CoE for its Z Fold series OLEDs, from Samsung Electronics' foldable phone Galaxy Z Fold 3 released in 2021 to this year's Z Fold 6. The black PDL required for this was made by Deoksan Neolux. For more, read the full report from The Elec.

With Apple's foldable projects beginning to take shape, LG Display is evidently out to experiment with foldable displays using similar technologies used in Samsung's foldable displays – which is a positive development, as it supports Kuo's research on the matter.