If reading on a dedicated e-reader or e ink tablet feels more natural than reading from a computer monitor, there is a good reason for it. Electronic paper displays (EPDs) utilize a special technology called electronic ink or electronic paper.
These display devices don’t emit light like a flat panel display. Instead, they use a light-reflecting e-ink screen that produces a similar look and feel to a conventional book or newspaper.
This is accomplished through many factors, but one of the greatest is contrast ratio, which is the right balance of light and dark for the viewing or reading environment. A well-designed e-ink monitor should be able to imitate the effect of reading a clearly-printed newspaper without interference or fading based on light levels. E-ink and e-paper display technology was based on a concept introduced in the 1970s.
The concept was later made viable in the mid-1990s through MIT-based startup E Ink Corporation. Their electronic paper display technology became a familiar feature after the mid-2000s, when e-readers like the PRS-500 Sony Reader, Amazon Kindle, and the Barnes and Nobel Nook hit the consumer electronics market. Although it’s not as flashy as other digital displays, it continues to drive innovation for new tech devices.
What Makes An eInk Display Special?
E-Ink and e-paper displays are important to more than bibliophiles; the high contrast, low-power digital medium has been used in status displays on portable devices, electronic labels, digital signage, EPD wristwatches, and other screens that need to display variable information with minimal power use. One of the more remarkable things about electronic paper displays is their utilization of pigments that are very similar to traditional print mediums.
e-Ink is contained in microcapsules that are suspended in a transparent fluid and are held between two electrodes. Changing the charge of the electrodes causes either light or dark ink capsules to appear at specific points on the screen, which then displays text or an image. This function is the same for e-readers and e-paper display screens that can display color.
Display capabilities are limited to pigment contained in the device, which means color range, sharpness, depth, and resolution are more limited compared to LCD and other flat-panel displays. But even as flat-panel displays have become more versatile, e-Ink displays offer special advantages in certain applications. The battery power is only required when an e-paper display needs to change what appears.
This isn’t ideal for smooth scrolling, but the turning of a page, changes in time or price, and simple animations are easily shown with minimal energy requirements. Since e-ink displays are not backlit, using them for long periods does not cause eyestrain that common with backlit monitors and tablet screens.
Liquid paper displays can be scaled up for high visibility at a distance or made quite compact for incorporation into small devices, including smartphones and tablets with dual displays.
An e-ink screen can be made extremely thin and even bendable, amounting to excellent durability for all types of devices, including wearables.
E-Ink Is Still Innovating
In recent years, electronic paper displays have been overshadowed by more dynamic visual technology, but they’re still relevant in today’s tech world. Reports of a new color-display, foldable device from E Ink, which is rumored to be in tests by Apple, may hint at a new generation of foldable tablets and i-Phones.
The quest for more compact digital devices with fewer power requirements could also fuel new applications of e-ink screens, especially where immediate responsiveness isn’t a primary requirement.