When Japan Display Inc. broke ground on a new factory in central Japan in 2015, the future looked bright for one of the world's top vendors of liquid crystal display (LCD) panels.

The plant would strengthen the company's position as the primary screen supplier for Apple Inc. as sales of the iPhone 6 soared. And the U.S. smartphone juggernaut said it would front most of the $1.5 billion in costs, with Japan Display paying it back with a percentage of screen sales, according to two company sources.

Four years later, Apple's shifting fortunes have brought Japan Display to its knees and threaten to end Japan's long run as a leader in display technology.