Sharp has announced plans to deliver 4K smartphone screens next year. The Japanese company - which produces screens for Apple's iPhones and other manufacturers - says it can squeeze a 3,840 x 2,160 resolution into a 5.5in display.
The plans, spotted on a Sharp presentation slide by Phonearena.com, are the latest sign that mobile manufacturers are hellbent on squeezing even more pixels into their devices, despite the eye's inability to resolve that much detail in a device so small.
When Steve Jobs launched the iPhone 4, he claimed that the "Retina display" would make individual pixels imperceptible to the human eye at a pixel density of 326ppi, when the device was held between 10 and 12 inches from the eye. The 4K display being touted by Sharp will have a pixel density of 806ppi, more than double Jobs'"magic number".
The iPhone 6 Plus has a 5.5in display with a Full HD resolution (1,920 x 1,080), equating to 401ppi. Sharp's display could conceivably make it into the generation after next of Apple's super-sized smartphone, although other manufacturers are already believed to be working on 4K displays for their premium devices.
The Samsung Galaxy Note 5 is rumoured to be shipping with a 4K display. Samsung manufacturers its own displays, potentially giving the company a headtstart over Apple, for whom it also supplies display equipment.
Pushing eight million pixels around a screen will have obvious implications for battery life, which is already one of the biggest shortcomings of most high-end smartphones. The performance of components inside smarthphones has far outstripped the ability of lithium-ion batteries, with manufacturers desperately researching next-generation battery technologies that can cope with such demanding applications.
The ARM Cortex-A72 processor announced earlier this year offered support for 4K video capture at 120 frames per second and "console-quality games". That processor is also set to arrive in 2016, and could conceivably be used in conjunction with Sharp's high-end screen.