e-Ink iPhone display could combine Apple quality with near-zero impact on battery life

According to a report, we might see an eInk iPhone screen in the near future. It will be used as a secondary display on a folded iPhone.

The most likely interpretation of a follow-up tweet is that Apple is testing a type of color e-ink display that offers crisper text, brighter displays, and richer colors than conventional technology …

Background

eInk, also known as ePaper displays, is best-known for its use in Amazon Kindles and other ebook readers. These displays combine the advantages of paper appearance and low power consumption.

The first generations of e-ink displays were mono – black on white, or vice-versa – but color is now supported.

The main problem with e-Ink is the slow refresh. This is acceptable for ebook usage, when you’re only going to be “turning the page” every 30 seconds or so, but not suitable for the type of dynamic usage needed for things like the primary displays of smartphones or laptops (even if one company disagrees). However, they can be suitable for secondary displays, with less dynamic content.

How might an e-Ink iPhone display be used?

Ming-Chi Kuo, an Apple analyst said that Apple is interested in folding devices. The company is expected to launch a folding iPhone at some point, which typically calls for a secondary display visible while the device is folded. Typical uses for this are to display the time, and notifications.

Existing folding smartphones use OLED for their external displays, but it would make a lot of sense to use an e-Ink one. The type of content displayed on a secondary display doesn’t change often, making the refresh rate unimportant. Typically, a user will only look at the display to quickly check the time, or to view a notification after an alert.

The big advantage of this is that the secondary display would use only a trickle of battery power, compared to even the type of low-refresh rate OLED used for the always-on feature of recent and current Apple Watches.

What e-Ink tech might Apple use?

While e-Ink and ePaper are used as generic terms for this type of display, Kuo said in a follow-up tweet that he was referring to a specific company.

The company offers a display module branded Kaleido, and it’s likely that Apple is testing the Plus variant.

Kaleido displays offer 16 levels of grayscale and are capable of displaying 4096 colors, enable ultra low power and high mobility devices with a paper-like experience, ideal for image-rich information applications such as charts, graphs, maps, photos, comics and advertising. Kaleido displays, which are similar to E Ink’s monochrome ePaper product, can be seen in direct sunlight and display crisp text as well as detailed color graphics.

The new printing process eliminates the requirement for a CFA glass-based. This makes the displays lighter and more compact than before, but also gives them a higher optical quality […]

In [the Plus], we have made some adjustments to the printed CFA [Color Filter Array], in order to improve color balance and texture. We also brought the CFA closer the ink to decrease light scattering. The new image rendering algorithms enable crisper text. In addition, we have made adjustments to the light guides, allowing for better optimization of the LED color spectrum to minimize color blending.

It would seem that this could offer the display quality we’d expect from an Apple device, coupled to a power draw so negligible that there would be no practical impact on battery life.

This assumes that an iPhone folding is launched at some point, which isn’t a certainty.

What are your thoughts? Please let us know in the comments.

Concept image: iOSBetaNews