Name the product, then the record that reframes it. A foldable phone is, to a buyer, one object that bends. To an engineer it is two distinct hard problems: the hinge that controls the fold, and the display that has to survive being folded. Samsung Display's granted patent US11137800B2, "Foldable display device," issued October 5, 2021, plants a claim firmly in the second category. Its CPC class G06F 1/1652 is the foldable-display construction class — it is about the panel, not the mechanism.
What it costs, what it earns, who owns it. The hinge determines whether the phone feels solid; the panel determines whether it survives a hundred thousand folds without a crease becoming a crack. By 2021, the hinge was a relatively solved, supplier-competitive problem, while the flexible OLED panel — substrate, encapsulation, the neutral-bending-plane stack — remained the expensive, failure-prone component. A grant on the foldable display device is a claim on the part of the bill-of-materials that still hurt.
The shift in classification across years is the analysis. The 2019-era Samsung foldable grants leaned on hinge classes; this 2021 grant leans on the display-construction class. Reading the portfolio as a sequence, you can watch the company's claims migrate from the mechanism to the screen as each layer of the problem got harder and more proprietary.
There is also a corporate-structure tell. This patent is assigned to Samsung Display Co., Ltd., the panel-making subsidiary, not Samsung Electronics, the device maker. The foldable IP lives partly in the components arm because that is where the durable, license-able advantage sits — Samsung Display sells panels to competitors, and the panel patents are the asset.
Scope discipline: this is a granted patent, and the foldable-display class is genuinely crowded — Semiconductor Energy Laboratory, LG Display, and others hold dense portfolios there. The grant is one position in a thicket, not a fence around foldables.
Follow the filing. When the next foldable launches, the spec sheet will brag about the hinge, but the durability and the cost will live in the panel — and the 2021 docket shows Samsung Display had already moved its claims there.