SAN JOSE, Calif. — A smartphone that unfolds into a tablet could emerge next year in an effort to reinvigorate the maturing mobile market. A bendable screen passed U.S. safety tests, Samsung Display announced late last week, in the latest sign that the long-rumored concept may be about to become a reality.

Engineers have worked for years on versions of flexible, even roll-able, displays. They aim to enable mobile devices in new form factors, opening new markets.

A smartphone with a bendable OLED display could open to a 7- to 8-inch screen size, delivering perhaps UHD resolution at 120 Hz. It would need to withstand at least 100,000 open/close cycles and could cost as much as $2,000, said Y.J. Kim, chief executive of MagnaChip, an independent maker of display driver chips for OLEDs.

If offered an $1,800 handset that could double as a tablet, “I’d buy it,” said Kim, adding that he has no knowledge of any commercial products in the works.

Kim and others said that Samsung and LG are the display makers most likely to have a bendable screen ready for commercialization. They would likely reserve such a component for their own handsets and make the driver ICs themselves.

For years, the South Korean conglomerates and others, including Microsoft’s Surface group, have been showing sometimes-crude prototypes — generally under non-disclosure agreements to spark enthusiasm for the concept. Most recently, Nikkei reported that Huawei could use flexible screens from China’s BOE to beat Samsung to market with a foldable phone, although BOE might only be able to supply such displays in low volumes.

Last year, China’s ZTE rolled out a foldable handset based on two displays on a hinge. The device initially received mixed reviews, suggesting that foldables could remain a novelty with little market traction.

“I think we will see something in 2019 because 5G is coming and it will have added costs, so if you already have a sizable jump, why not throw in something new?” said Wayne Lam, a principal mobile analyst at IHS Markit, adding that a small bendable display could double as a smartphone.

Even an $1,800 handset could be a net-cost savings compared to a high-end handset and a good tablet, said Kim of MagnaChip. Separately, Samsung has been showing smartphone displays encased in plastic rather than glass, enabling a lighter, more robust handset that would more likely to be a market hit.

Whether bendable or plastic-encased OLEDs enable significant new handset markets or not, smartphone makers clearly need to find new growth engines.

Smartphone sales in the last quarter of 2017 experienced their first year-over-year downturn, according to market watchers at Gartner. International Data Corp reported that smartphone sales declined a fraction of a percent in 2017 overall but predicted that they will grow at about a 2.4% rate over the next five years.

A prototype of a foldable OLED smartphone.
A prototype of a foldable OLED smartphone.

— Rick Merritt, Silicon Valley Bureau Chief, EE Times