As the single largest purchaser of small device displays, Apple wields enormous power over the screen manufacturers. Its main suppliers – Samsung, LG, Japan Display and Sharp – all create specialized designs and even processes to support the iDevices. To date, the company has stuck with LCD technology for its iPhone displays, but may switch to OLED – as used by most of its high end smartphone rivals – from 2018, and even earlier for the iPad. That, in turn, could prompt another shake-up in the already precarious small display sector. Last week, shares in Japanese component vendors slid on reports that Apple would adopt OLED iPhone displays in 2018, a decision which would probably accelerate the ongoing movements away…